Charging device and method, power adapter and terminal

ABSTRACT

The present disclosure discloses a charging device, a charging method, a power adapter and a terminal. The charging device includes a charging receiving terminal, a voltage adjusting circuit and a central control module. The charging receiving terminal is configured to receive an alternating current. The voltage adjusting circuit includes a first rectifier, a switch unit, a transformer and a second rectifier. The first rectifier is configured to rectify the alternating current and output a first voltage. The switch unit is configured to modulate the first voltage to output a modulated first voltage. The transformer is configured to output a second voltage according to the modulated first voltage. The second rectifier is configured to rectify the second voltage to output a third voltage. The voltage adjusting circuit applies the third voltage to a battery directly.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.15/955,658, filed on Apr. 17, 2018, which is a continuation of U.S.application Ser. No. 15/646,174, filed on Jul. 11, 2017, which claimspriority and benefits of Chinese Application No. 201610599657.3, filedon Jul. 26, 2016. The entire contents of the aforementioned applicationsare incorporated by reference herein.

TECHNICAL FIELD

The present disclosure generally relates to a terminal chargingtechnical field, and more particularly, to a charging device, a chargingmethod, a power adapter and a terminal.

BACKGROUND

Nowadays, mobile terminals such as smart phones are favored by more andmore consumers. However, the mobile terminal consumes large powerenergy, and needs to be charged frequently.

Typically, the mobile terminal is charged by a power adapter. The poweradapter generally includes a primary rectifier circuit, a primary filtercircuit, a transformer, a secondary rectifier circuit, a secondaryfilter circuit and a control circuit, such that the power adapterconverts the input alternating current of 220V into a stable and lowvoltage direct current (for example, 5V) suitable for requirements ofthe mobile terminal, and provides the direct current to a powermanagement device and a battery of the mobile terminal, therebyrealizing charging the mobile terminal.

However, with the increasing of the power of the power adapter, forexample, from 5 W to larger power such as 10 W, 15 W, 25 W, it needsmore electronic elements capable of bearing large power and realizingbetter control for adaptation, which not only increases a size of thepower adapter, but also increases a production cost and manufacturedifficulty of the power adapter.

SUMMARY

Embodiments of the present disclosure provide a charging device. Thecharging device includes a charging receiving terminal, a voltageadjusting circuit and a central control module. The charging receivingterminal is configured to receive an alternating current. The voltageadjusting circuit, having an input end coupled to the charging receivingterminal, and includes: a first rectifier, a switch unit, a transformerand a second rectifier. The first rectifier is configured to rectify thealternating current and output a first voltage with a first pulsatingwaveform. The switch unit is configured to modulate the first voltageaccording to a control signal to output a modulated first voltage. Thetransformer is configured to output a second voltage with a secondpulsating waveform according to the modulated first voltage. The secondrectifier is configured to rectify the second voltage to output a thirdvoltage with a third pulsating waveform. The voltage adjusting circuithas an output end configured to be coupled to a battery such that thethird voltage is directly applied to the battery. The central controlmodule is configured to output the control signal to the switch unit soas to adjust voltage and/or current outputted by the voltage adjustingcircuit, in response to a charging requirement of the battery.

Embodiments of the present disclosure provide a charging method. Thecharging method includes: receiving an alternating current; rectifyingthe alternating current to output a first voltage with a pulsatingwaveform, and modulating the first voltage to obtain a modulated firstvoltage; converting the modulated first voltage to a second voltage witha second pulsating waveform, and rectifying the second voltage to outputa third voltage with a third pulsating waveform; and directly applyingthe third voltage to a battery so as to charge the battery.

Embodiments of the present disclosure provide a power adapter. The poweradapter includes a first rectifier, configured to rectify an inputtingalternating current and output a first voltage with a first pulsatingwaveform; a switch unit, configured to modulate the first voltageaccording to a control signal to output a modulated first voltage; atransformer, configured to output a second voltage with a secondpulsating waveform according to the modulated first voltage; and asecond rectifier, configured to rectify the second voltage to output athird voltage with a third pulsating waveform to a battery of aterminal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating a charging system for aterminal using a flyback switching power supply according to anembodiment of the present disclosure.

FIG. 2 is a schematic diagram illustrating a charging system for aterminal using a forward switching power supply according to anembodiment of the present disclosure.

FIG. 3 is a schematic diagram illustrating a charging system for aterminal using a push-pull switching power supply according to anembodiment of the present disclosure.

FIG. 4 is a schematic diagram illustrating a charging system for aterminal using a half-bridge switching power supply according to anembodiment of the present disclosure.

FIG. 5 is a schematic diagram illustrating a charging system for aterminal using a full-bridge switching power supply according to anembodiment of the present disclosure.

FIG. 6 is a block diagram of a charging system for a terminal accordingto embodiments of the present disclosure.

FIG. 7 is a schematic diagram illustrating a waveform of a chargingvoltage outputted to a battery from a power adapter according to anembodiment of the present disclosure.

FIG. 8 is a schematic diagram illustrating a waveform of a chargingcurrent outputted to a battery from a power adapter according to anembodiment of the present disclosure.

FIG. 9 is a schematic diagram illustrating a control signal outputted toa switch unit according to an embodiment of the present disclosure.

FIG. 10 is a schematic diagram illustrating a fast charging processaccording to an embodiment of the present disclosure.

FIG. 11 is a schematic diagram illustrating a charging system for aterminal according to an embodiment of the present disclosure.

FIG. 12 is a schematic diagram illustrating a power adapter with a LCfilter circuit according to an embodiment of the present disclosure.

FIG. 13 is a schematic diagram illustrating a charging system for aterminal according to another embodiment of the present disclosure.

FIG. 14 is a schematic diagram illustrating a charging system for aterminal according to yet another embodiment of the present disclosure.

FIG. 15 is a schematic diagram illustrating a charging system for aterminal according to still another embodiment of the presentdisclosure.

FIG. 16 is a block diagram of a sampling unit according to an embodimentof the present disclosure.

FIG. 17 is a schematic diagram illustrating a charging system for aterminal according to still yet another embodiment of the presentdisclosure.

FIG. 18 is a schematic diagram illustrating a terminal according to anembodiment of the present disclosure.

FIG. 19 is a schematic diagram illustrating a terminal according toanother embodiment of the present disclosure.

FIG. 20 is a flow chart of a charging method for a terminal according toembodiments of the present disclosure.

FIG. 21 is a block diagram of a charging device according to embodimentsof the present disclosure.

FIG. 22 is a block diagram of a power adapter according to an embodimentof the present disclosure.

FIG. 23 is a block diagram of a terminal according to an embodiment ofthe present disclosure.

FIG. 24 is a flow chart of a charging method according to an embodimentof the present disclosure.

DETAILED DESCRIPTION

Descriptions will be made in detail to embodiments of the presentdisclosure, examples of which are illustrated in drawings, in which thesame or similar elements and the elements having same or similarfunctions are denoted by like reference numerals throughout thedescriptions. The embodiments described herein with reference todrawings are explanatory, are intended to understand the presentdisclosure, and are not construed to limit the present disclosure.

The present disclosure is made based on following understanding andresearches.

The inventors find that, during a charging to a battery of a mobileterminal by a power adapter, with the increasing of power of the poweradapter, it is easy to cause an increase in polarization resistance ofthe battery and temperature of the battery, thus reducing a service lifeof the battery, and affecting a reliability and a safety of the battery.

Moreover, most devices cannot work directly with alternating currentwhen the power is usually supplied with the alternating current, becausethe alternating current such as mains supply of 220V and 50 Hz outputselectric energy discontinuously. In order to avoid the discontinuity, itneeds to use an electrolytic condenser to store the electric energy,such that when the power supply is in the trough period, it is possibleto depend on the electric energy stored in the electrolytic condenser toensure a continuous and stable power supply. Thus, when an alternatingcurrent power source charges the mobile terminal via the power adapter,the alternating current such as the alternating current of 220V providedby the alternating current power source is converted into stable directcurrent, and the stable direct current is provided to the mobileterminal. However, the power adapter charges the battery in the mobileterminal so as to supply power to the mobile terminal indirectly, andthe continuity of power supply can be guaranteed by the battery, suchthat it is unnecessary for the power adapter to output stable andcontinue direct current when charging the battery.

In the following, a charging system for a terminal, a power adapter anda charging method for a terminal, a charging device and a chargingmethod provided in embodiments of the present disclosure will bedescribed with reference to drawings.

As illustrated in FIG. 21, a charging device 1000 according toembodiments of the present disclosure includes a charging receivingterminal 1001, a voltage adjusting circuit 1002 and a central controlmodule 1003.

The charging receiving terminal 1001 is configured to receive analternating current from a mains supply. An input end of the voltageadjusting circuit 1002 is coupled to the charging receiving terminal1001. The voltage adjusting circuit 1002 includes a first rectifier 101,a switch unit 102, a transformer 103, and a second rectifier 104. Thefirst rectifier 101 is configured to rectify the alternating current andoutput a first voltage with a first pulsating waveform. The switch unit102 is configured to modulate the first voltage according to a controlsignal to output a modulated first voltage. The transformer 103 isconfigured to output a second voltage with a second pulsating waveformaccording to the modulated first voltage. The second rectifier 104 isconfigured to rectify the second voltage to output a third voltage witha third pulsating waveform. An output end of the voltage adjustingcircuit 1002 is configured to be coupled to a battery (for example abattery 202 of the terminal) such that the third voltage is directlyapplied to the battery 202. In other words, the voltage adjustingcircuit 1002 is configured to adjust the alternating current form themains supply to output the voltage with the pulsating waveform, such asthe third voltage with the third pulsating waveform, and to applydirectly the third voltage to the battery so as to charge the battery.

The central control module 1003 is configured to output the controlsignal to the switch unit 102 so as to adjust voltage and/or currentoutputted by the voltage adjusting circuit 1002, in response to acharging requirement of the battery.

With the charging device according to embodiments of the presentdisclosure, by adjusting the alternating current from the mains supply,the voltage with the pulsating waveform meeting the charging requirementof the battery can be outputted, and can be directly applied to thebattery, thus realizing fast charging to the battery. In contrast to theconventional constant voltage and constant current, a lithiumprecipitation of the lithium battery may be reduced, the service life ofthe battery may be improved, and a probability and intensity of arcdischarge of a contact of a charging interface may be reduced, theservice life of the charging interface may be prolonged, and it isbeneficial to reduce polarization effect of the battery, improvecharging speed, and decrease the heat emitted by the battery, thusensuring a reliability and safety of battery during the charging.

According to an embodiment of the present disclosure, the centralcontrol module 1003 is further configured to obtain status informationof the battery 202, and to adjust the voltage and/or the currentoutputted by the voltage adjusting circuit 1002 according to the statusinformation of the battery 202. The adjustment will be described infollowing embodiments.

According to an embodiment of the present disclosure, the voltageadjusting circuit 1002 employs any one of a flyback switching powersupply, a forward switching power supply, a push-pull switching powersupply, a half-bridge switching power supply and a full-bridge switchingpower supply. In other words, the charging device according toembodiments of the present disclosure may utilize a principle of theflyback switching power supply, a principle of the forward switchingpower supply, a principle of the push-pull switching power supply, aprinciple of the half-bridge switching power supply or a principle ofthe full-bridge switching power supply, to convert the alternatingcurrent from the mains supply into the third voltage with the thirdpulsating waveform.

According to an embodiment of the present disclosure, as illustrated inFIG. 22, the charging device 1000 may be configured to be built in apower adapter 1.

According to an embodiment of the present disclosure, as illustrated inFIG. 23, the charging device 1000 may be configured to be built in aterminal 2.

With the charging device according to embodiments of the presentdisclosure, the alternating current from the mains supply can beconverted into the third voltage with the third pulsating waveform, andthe output third voltage is directly applied to the battery, thusrealizing fast charging to the battery directly by the pulsating outputvoltage/current. In contrast to the conventional constant voltage andconstant current, a magnitude of the pulsating output voltage/currentchanges periodically, such that a lithium precipitation of the lithiumbattery may be reduced, the service life of the battery may be improved,and a probability and intensity of arc discharge of a contact of acharging interface may be reduced, the service life of the charginginterface may be prolonged, and it is beneficial to reduce polarizationeffect of the battery, improve charging speed, and decrease the heatemitted by the battery, thus ensuring a reliability and safety ofbattery during the charging. Moreover, since voltage with the pulsatingwaveform is outputted, it is unnecessary to provide an electrolyticcondenser, which not only realizes simplification and miniaturization ofthe charging device, but also decreases cost greatly.

As illustrated in FIG. 24, embodiments of the present disclosure furtherprovide a charging method. The charging method includes the followings.

At block S10, an alternating current is received.

At block S20, the alternating current is rectified to output a firstvoltage with a first pulsating waveform, and the first voltage ismodulated to obtain a modulated first voltage.

At block S30, the modulated first voltage is converted into a secondvoltage with a second pulsating waveform, and the second voltage isrectified to output a third voltage with a third pulsating waveform.

At block S40, the third voltage is directly applied to a battery tocharge the battery.

The above charging method further includes: obtaining status informationof the battery, and adjusting voltage and/or current applied to thebattery according to the status information of the battery, in responseto a charging requirement of the battery.

According to an embodiment of the present disclosure, a waveform of themodulated first voltage keeps synchronous with the third pulsatingwaveform.

With the charging method according to embodiments of the presentdisclosure, the alternating current from the mains supply can beconverted into the third voltage with the third pulsating waveform, andthe outputted third voltage is directly applied to the battery, thusrealizing fast charging to the battery directly by the pulsating outputvoltage/current. In contrast to the conventional constant voltage andconstant current, a magnitude of the pulsating output voltage/currentchanges periodically, such that a lithium precipitation of the lithiumbattery may be reduced, the service life of the battery may be improved,and a probability and intensity of arc discharge of a contact of acharging interface may be reduced, the service life of the charginginterface may be prolonged, and it is beneficial to reduce polarizationeffect of the battery, improve charging speed, and decrease the heatemitted by the battery, thus ensuring a reliability and safety ofbattery during the charging. Moreover, since voltage with the pulsatingwaveform is outputted, it is unnecessary to provide an electrolyticcondenser, which not only realizes simplification and miniaturization ofthe charging device, but also decreases cost greatly.

Embodiments of the present disclosure provide a power adapter. The poweradapter is configured to perform the above charging method.

With the power adapter according to embodiments of the presentdisclosure, by performing the above charging method, the third voltagewith the third pulsating waveform is outputted, and the third voltage isdirectly applied to the battery of the terminal, thus realizing fastcharging to the battery directly by the pulsating outputvoltage/current. In contrast to the conventional constant voltage andconstant current, a magnitude of the pulsating output voltage/currentchanges periodically, such that a lithium precipitation of the lithiumbattery may be reduced, the service life of the battery may be improved,and a probability and intensity of arc discharge of a contact of acharging interface may be reduced, the service life of the charginginterface may be prolonged, and it is beneficial to reduce polarizationeffect of the battery, improve charging speed, and decrease the heatemitted by the battery, thus ensuring a reliability and safety duringthe charging. Moreover, since voltage with the pulsating waveform isoutputted, it is unnecessary to provide an electrolytic condenser, whichnot only realizes simplification and miniaturization of the poweradapter, but also decreases cost greatly.

Embodiments of the present disclosure provide a terminal. The terminalis configured to perform the above charging method.

With the terminal according to embodiments of the present disclosure, byperforming the above charging method, the alternating current from themains supply can be converted into the third voltage with the thirdpulsating waveform, and the third voltage is directly applied to thebattery in the terminal, thus realizing fast charging to the batterydirectly by the pulsating output voltage/current. In contrast to theconventional constant voltage and constant current, a magnitude of thepulsating output voltage/current changes periodically, such that alithium precipitation of the lithium battery may be reduced, the servicelife of the battery may be improved, and it is beneficial to reducepolarization effect of the battery, improve charging speed, and decreasethe heat emitted by the battery, thus ensuring a reliability and safetyof the terminal during the charging. Moreover, since voltage with thepulsating waveform is outputted, it is unnecessary to provide anelectrolytic condenser, which not only decreases occupied space, butalso decreases cost greatly.

A process of charging the battery by using the voltage with thepulsating waveform provided in embodiments of the present disclosurewill be described in detail with reference to accompany drawings.

Referring to FIGS. 1-14, the charging system for the terminal providedin embodiments of the present disclosure includes a power adapter 1 anda terminal 2.

As illustrated in FIG. 6, the power adapter 1 includes a first rectifier101, a switch unit 102, a transformer 103, a second rectifier 104, afirst charging interface 105, a sampling unit 106, and a control unit107. The first rectifier 101 is configured to rectify an inputalternating current (AC for short, mains supply, for example AC 220V) tooutput a first voltage with a first pulsating waveform, for example avoltage with a steamed bun waveform. As illustrated in FIG. 1, the firstrectifier 101 may be a full-bridge rectifier formed of four diodes. Theswitch unit 102 is configured to modulate the first voltage with thefirst pulsating waveform according to a control signal to output amodulated first voltage. The switch unit 102 may be formed of MOStransistors. A PWM (Pulse Width Modulation) control is performed on theMOS transistors to perform a chopping modulation on the voltage with thesteamed bun waveform. The transformer 103 is configured to output asecond voltage with a second pulsating waveform according to themodulated first voltage. The second rectifier 104 is configured torectify the second voltage to output a third voltage with a thirdpulsating waveform. The second rectifier 104 may include a diode or aMOS transistor, and can realize a secondary synchronous rectification,such that the third pulsating waveform keeps synchronous with a waveformof the modulated first voltage. It should be noted that, the thirdpulsating waveform keeping synchronous with the waveform of themodulated first voltage means that, a phase of the third pulsatingwaveform is consistent with that of the waveform of the modulated firstvoltage, and a variation trend of magnitude of the third pulsatingwaveform is consistent with that of the waveform of the modulated firstvoltage. The first charging interface 105 is coupled to the secondrectifier 104. The sampling unit 106 is configured to sample voltageand/or current outputted by the second rectifier 104 to obtain a voltagesampling value and/or a current sampling value. The control unit 107 isarranged at a secondary side of the transformer 103. The control unit107 is coupled to the sampling unit 106 and the switch unit 102respectively. The control unit 107 is configured to output the controlsignal to the switch unit 102, to adjust a duty ratio of the controlsignal according to the current sampling value and/or the voltagesampling value, such that the third voltage outputted by the secondrectifier 104 meets a charging requirement.

As illustrated in FIG. 6, the terminal 2 includes a second charginginterface 201 and a battery 202. The second charging interface 201 iscoupled to the battery 202. When the second charging interface 201 iscoupled to the first charging interface 105, the second charginginterface 201 is configured to apply the third voltage with the thirdpulsating waveform to the battery 202, so as to charge the battery 202.

In an embodiment of the present disclosure, as illustrated in FIG. 1,the power adapter 1 may adopt a flyback switching power supply. Thetransformer 103 includes a primary winding and a secondary winding. Anend of the primary winding is coupled to a first output end of the firstrectifier 101. A second output end of the first rectifier 101 isgrounded. Another end of the primary winding is coupled to the switchunit 102 (for example, if the switch unit 102 is a MOS transistor, theother end of the primary winding is coupled to a drain of the MOStransistor). The transformer 103 is configured to output a secondvoltage with a second pulsating waveform according to the modulatedfirst voltage.

The transformer 103 is a high-frequency transformer of which a workingfrequency ranges from 50 KHz to 2 MHz. The high-frequency transformer isconfigured to couple the modulated first voltage to the secondary sideso as to output via the secondary winding. In embodiments of the presentdisclosure, with the high-frequency transformer, a characteristic of asmall size compared to the low-frequency transformer (also known as anindustrial frequency transformer, mainly used in the frequency of mainssupply such as alternating current of 50 Hz or 60 Hz) may be exploitedto realize miniaturization of the power adapter 1.

In an embodiment of the present disclosure, as illustrated in FIG. 2,the power adapter 1 may also adopt a forward switching power supply. Indetail, the transformer 103 includes a first winding, a second windingand a third winding. A dotted terminal of the first winding is coupledto a second output end of the first rectifier 101 via a backward diode.A non-dotted terminal of the first winding is coupled to a dottedterminal of the second winding and then coupled to a first output end ofthe first rectifier 101. A non-dotted terminal of the second winding iscoupled to the switch unit 102. The third winding is coupled to thesecond rectifier 104. The backward diode is configured to realizereverse peak clipping. An induced potential generated by the firstwinding may perform amplitude limiting on a reverse potential via thebackward diode and return limited energy to an output of the firstrectifier 101, so as to charge the output of the first rectifier 101.Moreover, a magnetic field generated by current flowing through thefirst winding may demagnetize a core of the transformer, so as to returnmagnetic field intensity in the core of the transformer to an initialstate. The transformer 103 is configured to output the second voltagewith the second pulsating waveform according to the modulated firstvoltage.

According to an embodiment of the present disclosure, as illustrated inFIG. 3, the above-mentioned power adapter 1 may adopt a push-pullswitching power supply. In detail, the transformer includes a firstwinding, a second winding, a third winding and a fourth winding. Adotted terminal of the first winding is coupled to the switch unit 102.A non-dotted terminal of the first winding is coupled to a dottedterminal of the second winding and then coupled to the first output endof the first rectifier 101. A non-dotted terminal of the second windingis coupled to the switch unit 102. A non-dotted terminal of the thirdwinding is coupled to a dotted terminal of the fourth winding. Thetransformer is configured to output the second voltage with the secondpulsating waveform according to the modulated first voltage.

As illustrated in FIG. 3, the switch unit 102 includes a first MOStransistor Q1 and a second MOS transistor Q2. The transformer 103includes a first winding, a second winding, a third winding and a fourthwinding. A dotted terminal of the first winding is coupled to a drain ofthe first MOS transistor Q1 in the switch unit 102. A non-dottedterminal of the first winding is coupled to a dotted terminal of thesecond winding. A node between the non-dotted terminal of the firstwinding and the dotted terminal of the second winding is coupled to thefirst output end of the first rectifier 101. A non-dotted terminal ofthe second winding is coupled to a drain of the second MOS transistor Q2in the switch unit 102. A source of the first MOS transistor Q1 iscoupled to a source of the second MOS transistor Q2 and then coupled tothe second output end of the first rectifier 101. A dotted terminal ofthe third winding is coupled to a first input end of the secondrectifier 104. A non-dotted terminal of the third winding is coupled toa dotted terminal of the fourth winding. A node between the non-dottedterminal of the third winding and the dotted terminal of the fourthwinding is grounded. A non-dotted terminal of the fourth winding iscoupled to a second input end of the second rectifier 104.

As illustrated in FIG. 3, the first input end of the second rectifier104 is coupled to the dotted terminal of the third winding, and thesecond input end of the second rectifier 104 is coupled to thenon-dotted terminal of the fourth winding. The second rectifier 104 isconfigured to rectify the second voltage with the second pulsatingwaveform and to output the third voltage with the third pulsatingwaveform. The second rectifier 104 may include two diodes. An anode ofone diode is coupled to the dotted terminal of the third winding. Ananode of another diode is coupled to a non-dotted terminal of the fourthwinding. A cathode of one diode is coupled to that of the other diode.

According to an embodiment of the present disclosure, as illustrated inFIG. 4, the above-mentioned power adapter 1 may also adopt a half-bridgeswitching power supply. In detail, the switch unit 102 includes a firstMOS transistor Q1, a second MOS transistor Q2, a first capacitor C1 anda second capacitor C2. The first capacitor C1 and the second capacitorC2 are coupled in series, and then coupled in parallel to the outputends of the first rectifier 101. The first MOS transistor Q1 and thesecond MOS transistor Q2 are coupled in series, and then coupled inparallel to the output ends of the first rectifier 101. The transformer103 includes a first winding, a second winding and a third winding. Adotted terminal of the first winding is coupled to a node between thefirst capacitor C1 and the second capacitor C2 coupled in series. Anon-dotted terminal of the first winding is coupled to a node betweenthe first MOS transistor Q1 and the second MOS transistor Q2 coupled inseries. A dotted terminal of the second winding is coupled to the firstinput end of the second rectifier 104. A non-dotted terminal of thesecond winding is coupled to a dotted terminal of the third winding, andthen grounded. A non-dotted terminal of the third winding is coupled tothe second input end of the second rectifier 104. The transformer 103 isconfigured to output the second voltage with the second pulsatingwaveform according to the modulated first voltage.

According to an embodiment of the present disclosure, as illustrated inFIG. 5, the above-mentioned power adapter 1 may also adopt a full-bridgeswitching power supply. In detail, the switch unit 102 includes a firstMOS transistor Q1, a second MOS transistor Q2, a third MOS transistor Q3and a fourth MOS transistor Q4. The third MOS transistor Q3 and thefourth MOS transistor Q4 are coupled in series and then coupled inparallel to the output ends of the first rectifier 101. The first MOStransistor Q1 and the second MOS transistor Q2 are coupled in series andthen coupled in parallel to the output ends of the first rectifier 101.The transformer 103 includes a first winding, a second winding and athird winding. A dotted terminal of the first winding is coupled to anode between the third MOS transistor Q3 and the fourth MOS transistorQ4 coupled in series. A non-dotted terminal of the first winding iscoupled to a node between the first MOS transistor Q1 and the second MOStransistor Q2 coupled in series. A dotted terminal of the second windingis coupled to the first input end of the second rectifier 104. Anon-dotted terminal of the second winding is coupled to a dottedterminal of the third winding, and then grounded. A non-dotted terminalof the third winding is coupled to the second input end of the secondrectifier 104. The transformer 103 is configured to output the secondvoltage with the second pulsating waveform according to the modulatedfirst voltage.

Therefore, in embodiments of the present disclosure, the above-mentionedpower adapter 1 may adopt any one of the flyback switching power supply,the forward switching power supply, the push-pull switching powersupply, the half-bridge switching power supply and the full-bridgeswitching power supply to output the voltage with the pulsatingwaveform.

Further, as illustrated in FIG. 1, the second rectifier 104 is coupledto the secondary winding of the transformer 103. The second rectifier104 is configured to rectifier the second voltage with the secondpulsating waveform to output a third voltage with a third pulsatingwaveform. The second rectifier 104 may include a diode, and can realizea secondary synchronous rectification, such that the third pulsatingwaveform keeps synchronous with a waveform of the modulated firstvoltage. It should be noted that, the third pulsating waveform keepingsynchronous with the waveform of the modulated first voltage means that,a phase of the third pulsating waveform is consistent with that of thewaveform of the modulated first voltage, and a variation trend ofmagnitude of the third pulsating waveform is consistent with that of thewaveform of the modulated first voltage. The first charging interface105 is coupled to the second rectifier 104. The sampling unit 106 isconfigured to sample voltage and/or current outputted by the secondrectifier 104 to obtain a voltage sampling value and/or a currentsampling value. The control unit 107 is coupled to the sampling unit 106and the switch unit 102 respectively. The control unit 107 is configuredto output the control signal to the switch unit 102, and to adjust aduty ratio of the control signal according to the current sampling valueand/or the voltage sampling value, such that the third voltage outputtedby the second rectifier 104 meets a charging requirement.

As illustrated in FIG. 1, the terminal 2 includes a second charginginterface 201 and a battery 202. The second charging interface 201 iscoupled to the battery 202. When the second charging interface 201 iscoupled to the first charging interface 105, the second charginginterface 201 is configured to apply the third voltage with the thirdpulsating waveform to the battery 202, so as to charge the battery 202.

It should be noted that, the third voltage with the third pulsatingwaveform meeting the charging requirement means that, the third voltageand current with the third pulsating waveform need to meet the chargingvoltage and charging current when the battery is charged. In otherwords, the control unit 107 is configured to adjust the duty ratio ofthe control signal (such as a PWM signal) according to the voltageand/or current outputted by the power adapter, so as to adjust theoutput of the second rectifier 104 in real time and realize aclosed-loop adjusting control, such that the third voltage with thethird pulsating waveform meets the charging requirement of the terminal2, thus ensuring the stable and safe charging of the battery 202. Indetail, a waveform of a charging voltage outputted to a battery 202 isillustrated in FIG. 7, in which the waveform of the charging voltage isadjusted according to the duty ratio of the PWM signal. A waveform of acharging current outputted to a battery 202 is illustrated in FIG. 8, inwhich the waveform of the charging current is adjusted according to theduty ratio of the PWM signal.

It can be understood that, when adjusting the duty ratio of the PWMsignal, an adjusting instruction may be generated according to thevoltage sampling value, or according to the current sampling value, oraccording to the voltage sampling value and the current sampling value.

Therefore, in embodiments of the present disclosure, by controlling theswitch unit 102, a PWM chopping modulation is directly performed on thefirst voltage with the first pulsating waveform i.e. the steamed bunwaveform after a rectification, and then a modulated voltage is sent tothe high-frequency transformer and is coupled from the primary side tothe secondary side via the high-frequency transformer, and then ischanged back to the voltage/current with the steamed bun waveform aftera synchronous rectification. The voltage/current with the steamed bunwaveform is directly transmitted to the battery so as to realize fastcharging to the battery. The magnitude of the voltage with the steamedbun waveform may be adjusted according to the duty ratio of the PWMsignal, such that the output of the power adapter may meet the chargingrequirement of the battery. It can be seen from that, the power adapteraccording to embodiments of the present disclosure, without providingelectrolytic condensers at the primary side and the secondary side, maydirectly charge the battery via the voltage with the steamed bunwaveform, such that a size of the power adapter may be reduced, thusrealizing miniaturization of the power adapter, and decreasing costgreatly.

In an embodiment of the present disclosure, the control unit 107 may bean MCU (micro controller unit), which means that the control unit 107may be a microprocessor integrated with a switch driving controlfunction, a synchronous rectification function, a voltage and currentadjusting control function.

According to an embodiment of the present disclosure, the control unit107 is further configured to adjust a frequency of the control signalaccording to the voltage sampling value and/or the current samplingvalue. That is, the control unit 107 is further configured to control tooutput the PWM signal to the switch unit 102 for a continuous timeperiod, and then to stop outputting for a predetermined time period andthen to restart to output the PWM signal. In this way, the voltageapplied to the battery is intermittent, thus realizing intermittentcharging of the battery, which avoids a safety hazard caused by heatingphenomenon occurring when the battery is charged continuously andimproves the reliability and safety of the charging to the battery.

Under a low temperature condition, since the conductivity of ions andelectrons in a lithium battery decreases, it is prone to intensifydegree of polarization during a charging process for the lithiumbattery. A continuous charging not only makes this polarization seriousbut also increases a possibility of lithium precipitation, thusaffecting safety performance of the battery. Furthermore, the continuouscharging may accumulate heat generated due to the charging, thus leadingto an increasing of internal temperature of the battery. When thetemperature exceeds a certain value, performance of the battery may belimited, and possibility of safety hazard is increased.

In embodiments of the present disclosure, by adjusting the frequency ofthe control signal, the power adapter outputs intermittently, whichmeans that a battery resting process is introduced into the chargingprocess, such that the lithium precipitation due to the polarizationduring the continuous charging is reduced and continuous accumulation ofgenerated heat may be avoided to realize drop in the temperature, thusensuring the safety and reliability of charging to the battery.

The control signal outputted to the switch unit 102 is illustrated inFIG. 9, for example. Firstly, the PWM signal is outputted for acontinuous time period, then output of the PWM signal is stopped for acertain time period, and then the PWM signal is outputted for acontinuous time period again. In this way, the control signal output tothe switch unit 102 is intermittent, and the frequency is adjustable.

As illustrated in FIG. 1, the control unit 107 is coupled to the firstcharging interface 105. The control unit 107 is further configured toobtain status information of the terminal 2 by performing acommunication with the terminal 2 via the first charging interface 105.In this way, the control unit 107 is further configured to adjust theduty ratio of the control signal (such as the PWM signal) according tothe status information of the terminal, the voltage sampling valueand/or the current sampling value.

The status information of the terminal includes an electric quantity ofthe battery, a temperature of the battery, a voltage of the battery,interface information of the terminal and information on a pathimpedance of the terminal.

In detail, the first charging interface 105 includes a power wire and adata wire. The power wire is configured to charge the battery. The datawire is configured to communicate with the terminal. When the secondcharging interface 201 is coupled to the first charging interface 105,communication query instructions may be transmitted by the power adapter1 and the terminal 2 to each other. A communication connection can beestablished between the power adapter 1 and the terminal 2 afterreceiving a corresponding reply instruction. The control unit 107 mayobtain the status information of the terminal 2, so as to negotiatedwith the terminal 2 about a charging mode and charging parameters (suchas the charging current, the charging voltage) and to control thecharging process.

The charging mode supported by the power adapter and/or the terminal mayinclude a first charging mode and a second charging mode. A chargingspeed of the second charging mode is faster than that of the firstcharging mode. For example, a charging current of the second chargingmode is greater than that of the first charging mode. In general, thefirst charging mode may be understood as a charging mode in which arated output voltage is 5V and a rated output current is less than orequal to 2.5 A. In addition, in the first charging mode, D+ and D− inthe data wire of an output port of the power adapter may beshort-circuited. On the contrary, in the second charging mode accordingto embodiments of the present disclosure, the power adapter may realizedata exchange by communicating with the terminal via D+ and D− in thedata wire, i.e., fast charging instructions may be sent by the poweradapter and the terminal to each other. The power adapter sends a fastcharging query instruction to the terminal. After receiving a fastcharging reply instruction from the terminal, the power adapter obtainsthe status information of the terminal and starts the second chargingmode according to the fast charging reply instruction. The chargingcurrent in the second charging mode may be greater than 2.5 A, forexample, may be 4.5 A or more. The first charging mode is not limited inembodiments of the present disclosure. As long as the power adaptersupports two charging modes one of which has a charging speed (orcurrent) greater than the other charging mode, the charging mode with aslower charging speed may be regarded as the first charging mode. As tothe charging power, the charging power in the second charging mode maybe greater than or equal to 15 W.

The control unit 107 communicates with the terminal 2 via the firstcharging interface 105 to determine the charging mode. The charging modeincludes the second charging mode and the first charging mode.

In detail, the power adapter is coupled to the terminal via a universalserial bus (USB) interface. The USB interface may be a general USBinterface, or a micro USB interface. A data wire in the USB interface isconfigured as the data wire in the first charging interface, andconfigured for a bidirectional communication between the power adapterand the terminal. The data wire may be D+ and/or D− wire in the USBinterface. The bidirectional communication may refer to an informationinteraction performed between the power adapter and the terminal.

The power adapter performs the bidirectional communication with theterminal via the data wire in the USB interface, so as to determine tocharge the terminal in the second charging mode.

It should be noted that, during a process that the power adapter and theterminal negotiate whether to charge the terminal in the second chargingmode, the power adapter may only keep a coupling with the terminal butdoes not charge the terminal, or charges the terminal in the firstcharging mode or charges the terminal with small current, which is notlimited herein.

The power adapter adjusts a charging current to a charging currentcorresponding to the second charging mode, and charges the terminal.After determining to charge the terminal in the second charging mode,the power adapter may directly adjust the charging current to thecharging current corresponding to the second charging mode or maynegotiate with the terminal about the charging current of the secondcharging mode. For example, the charging current corresponding to thesecond charging mode may be determined according to a current electricquantity of the battery of the terminal.

In embodiments of the present disclosure, the power adapter does notincrease the output current blindly for fast charging, but needs toperform the bidirectional communication with the terminal so as tonegotiate whether to adopt the second charging mode. In contrast to therelated art, the safety of fast charging is improved.

As an embodiment, when the control unit 107 performs the bidirectionalcommunication with the terminal via the first charging interface so asto determine to charge the terminal in the second charging mode, thecontrol unit 107 is configured to send a first instruction to theterminal and to receive a first reply instruction from the terminal. Thefirst instruction is configured to query the terminal whether to startthe second charging mode. The first reply instruction is configured toindicate that the terminal agrees to start the second charging mode.

As an embodiment, before the control unit sends the first instruction tothe terminal, the power adapter is configured to charge the terminal inthe first charging mode. The control unit is configured to send thefirst instruction to the terminal when determining that a chargingduration of the first charging mode is greater than a predeterminedthreshold.

It should be understood that, when the power adapter determines that thecharging duration of the first charging mode is greater than thepredetermined threshold, the power adapter may determine that theterminal has identified it as a power adapter, such that the fastcharging query communication may start.

As an embodiment, after determining the terminal is charged for apredetermined time period with a charging current greater than or equalto a predetermined current threshold, the power adapter is configured tosend the first instruction to the terminal.

As an embodiment, the control unit is further configured to control thepower adapter to adjust a charging current to a charging currentcorresponding to the second charging mode by controlling the switchunit. Before the power adapter charges the terminal with the chargingcurrent corresponding to the second charging mode, the control unit isconfigured to perform the bidirectional communication with the terminalvia the data wire of the first charging interface to determine acharging voltage corresponding to the second charging mode, and tocontrol the power adapter to adjust a charging voltage to the chargingvoltage corresponding to the second charging mode.

As an embodiment, when the control unit performs the bidirectionalcommunication with the terminal via the data wire of the first charginginterface to determine the charging voltage corresponding to the secondcharging mode, the control unit is configured to send a secondinstruction to the terminal, to receive a second reply instruction sentfrom the terminal, and to determine the charging voltage correspondingto the second charging mode according to the second reply instruction.The second instruction is configured to query whether a current outputvoltage of the power adapter is suitable for being used as the chargingvoltage corresponding to the second charging mode. The second replyinstruction is configured to indicate that the current output voltage ofthe power adapter is suitable, high or low.

As an embodiment, before controlling the power adapter to adjust thecharging current to the charging current corresponding to the secondcharging mode, the control unit is further configured to perform thebidirectional communication with the terminal via the data wire of thefirst charging interface to determine the charging current correspondingto the second charging mode.

As an embodiment, when performing the bidirectional communication withthe terminal via the data wire of the first charging interface todetermine the charging current corresponding to the second chargingmode, the control unit is configured to send a third instruction to theterminal, to receive a third reply instruction sent from the terminaland to determine the charging current corresponding to the secondcharging mode according to the third reply instruction. The thirdterminal is configured to query a maximum charging current supported bythe terminal. The third reply instruction is configured to indicate themaximum charging current supported by the terminal.

The power adapter may determine the above maximum charging current asthe charging current corresponding to the second charging mode, or mayset the charging current as a charging current less than the maximumcharging current.

As an embodiment, during a process that the power adapter charges theterminal in the second charging mode, the control unit is furtherconfigured to perform the bidirectional communication with the terminalvia the data wire of the first charging interface, so as to continuouslyadjust a charging current outputted to the battery from the poweradapter by controlling the switch unit.

The power adapter may query the status information of the terminalcontinuously, for example, query the voltage of the battery of theterminal, the electric quantity of the battery, etc., so as to adjustthe charging current outputted to the battery from the power adaptercontinuously.

As an embodiment, when the control unit performs the bidirectionalcommunication with the terminal via the data wire of the first charginginterface to continuously adjust the charging current outputted to thebattery from the power adapter by controlling the switch unit, thecontrol unit is configured to send a fourth instruction to the terminal,to receive a fourth reply instruction sent by the terminal, and toadjust the charging current outputted to the battery from the poweradapter by controlling the switch unit according to the current voltageof the battery. The fourth instruction is configured to query a currentvoltage of the battery in the terminal. The fourth reply instruction isconfigured to indicate the current voltage of the battery in theterminal.

As an embodiment, the control unit is configured to adjust the chargingcurrent outputted to the battery from the power adapter to a chargingcurrent value corresponding to the current voltage of the battery bycontrolling the switch unit according to the current voltage of thebattery and a predetermined correspondence between battery voltagevalues and charging current values.

In detail, the power adapter may store the correspondence betweenbattery voltage values and charging current values in advance. The poweradapter may also perform the bidirectional communication with theterminal via the data wire of the first charging interface to obtainfrom the terminal the correspondence between battery voltage values andcharging current values stored in the terminal.

As an embodiment, during the process that the power adapter charges theterminal in the second charging mode, the control unit is furtherconfigured to determine whether there is a poor contact between thefirst charging interface and the second charging interface by performingthe bidirectional communication with the terminal via the data wire ofthe first charging interface. When determining that there is the poorcontact between the first charging interface and the second charginginterface, the control unit is configured to control the power adapterto quit the second charging mode.

As an embodiment, before determining whether there is the poor contactbetween the first charging interface and the second charging interface,the control unit is further configured to receive information indicatinga path impedance of the terminal from the terminal. The control unit isconfigured to send a fourth instruction to the terminal. The fourthinstruction is configured to query a current voltage of the battery inthe terminal. The control unit is configured to receive a fourth replyinstruction sent by the terminal. The fourth reply instruction isconfigured to indicate the current voltage of the battery in theterminal. The control unit is configured to determine a path impedancefrom the power adapter to the battery according to an output voltage ofthe power adapter and the current voltage of the battery and determineswhether there is the poor contact between the first charging interfaceand the second charging interface according to the path impedance fromthe power adapter to the battery, the path impedance of the terminal,and a path impedance of a charging wire between the power adapter andthe terminal.

The terminal may record the path impedance thereof in advance. Forexample, since the terminals in a same type have a same structure, thepath impedance of the terminals in the same type is set to a same valuewhen configuring factory settings. Similarly, the power adapter mayrecord the path impedance of the charging wire in advance. When thepower adapter obtains the voltage cross two ends of the battery of theterminal, the path impedance of the whole path can be determinedaccording to the voltage drop cross two ends of the battery and currentof the path. When the path impedance of the whole path>the pathimpedance of the terminal+the path impedance of the charging wire, orthe path impedance of the whole path−(the path impedance of theterminal+the path impedance of the charging wire)>an impedancethreshold, it can be considered that there is the poor contact betweenthe first charging interface and the second charging interface.

As an embodiment, before the power adapter quits the second chargingmode, the control unit is further configured to send a fifth instructionto the terminal. The fifth instruction is configured to indicate thatthere is the poor contact between the first charging interface and thesecond charging interface.

After sending the fifth instruction, the power adapter may quit thesecond charging mode or reset.

The fast charging process according to embodiments of the presentdisclosure is described from the perspective of the power adapter, andthen the fast charging process according to embodiments of the presentdisclosure will be described from the perspective of the terminal in thefollowing.

It should be understood that, the interaction between the power adapterand the terminal, relative characteristics, functions described at theterminal side correspond to descriptions at the power adapter side, thusrepetitive description will be omitted for simplification.

According to an embodiment of the present disclosure, as illustrated inFIG. 18, the terminal 2 further includes a charging control switch 203and a controller 204. The charging control switch 203, such as a switchcircuit formed of an electronic switch element, is coupled between thesecond charging interface 201 and the battery 202, and is configured toswitch on or off a charging process of the battery 202 under a controlof the controller 204. In this way, the charging process of the battery202 can be controlled at the terminal side, thus ensuring the safety andreliability of charging to battery 202.

As illustrated in FIG. 19, the terminal 2 further includes acommunication unit 205. The communication unit 205 is configured toestablish a bidirectional communication between the controller 204 andthe control unit 107 via the second charging interface 201 and the firstcharging interface 105. In other words, the terminal 2 and the poweradapter 1 can perform the bidirectional communication via the data wirein the USB interface. The terminal 2 supports the first charging modeand the second charging mode. The charging current of the secondcharging mode is greater than that of the first charging mode. Thecommunication unit 205 performs the bidirectional communication with thecontrol unit 107 such that the power adapter 1 determines to charge theterminal 2 in the second charging mode, and the control unit 107controls the power adapter 1 to output according to the charging currentcorresponding to the second charging mode, for charging the battery 202in the terminal 2.

In embodiments of the present disclosure, the power adapter 1 does notincrease the output current blindly for the fast charging, but needs toperform the bidirectional communication with the terminal 2 to negotiatewhether to adopt the second charging mode. In contrast to the relatedart, the safety of the fast charging process is improved.

As an embodiment, the controller is configured to receive the firstinstruction sent by the control unit via the communication unit. Thefirst instruction is configured to query the terminal whether to startthe second charging mode. The controller is configured to send a firstreply instruction to the control unit via the communication unit. Thefirst reply instruction is configured to indicate that the terminalagrees to start the second charging mode.

As an embodiment, before the controller receives the first instructionsent by the control unit via the communication unit, the battery in theterminal is charged by the power adapter in the first charging mode.When the control unit determines that a charging duration of the firstcharging mode is greater than a predetermined threshold, the controlunit sends the first instruction to the communication unit in theterminal, and the controller receives the first instruction sent by thecontrol unit via the communication unit.

As an embodiment, before the power adapter outputs according to thecharging current corresponding to the second charging mode for chargingthe battery in the terminal, the controller is configured to perform thebidirectional communication with the control unit via the communicationunit, such that the power adapter determines the charging voltagecorresponding to the second charging mode.

As an embodiment, the controller is configured to receive a secondinstruction sent by the control unit, and to send a second replyinstruction to the control unit. The second instruction is configured toquery whether a current output voltage of the power adapter is suitablefor being used as the charging voltage corresponding to the secondcharging mode. The second reply instruction is configured to indicatethat the current output voltage of the power adapter is suitable, highor low.

As an embodiment, the controller is configured to perform thebidirectional communication with the control unit, such that the poweradapter determines the charging current corresponding to the secondcharging mode.

The controller is configured to receive a third instruction sent by thecontrol unit, in which the third instruction is configured to query amaximum charging current supported by the terminal. The controller isconfigured to send a third reply instruction to the control unit, inwhich the third reply instruction is configured to indicate the maximumcharging current supported by the terminal, such that the power adapterdetermines the charging current corresponding to the second chargingmode according to the maximum charging current.

As an embodiment, during a process that the power adapter charges theterminal in the second charging mode, the controller is configured toperform the bidirectional communication with the control unit, such thatthe power adapter continuously adjusts a charging current outputted tothe battery.

The controller is configured to receive a fourth instruction sent by thecontrol unit, in which the fourth instruction is configured to query acurrent voltage of the battery in the terminal. The controller isconfigured to send a fourth reply instruction to the control unit, inwhich the fourth reply instruction is configured to indicate the currentvoltage of the battery in the terminal, such that the power adaptercontinuously adjusts the charging current outputted to the batteryaccording to the current voltage of the battery.

As an embodiment, during the process that the power adapter charges theterminal in the second charging mode, the controller is configured toperform the bidirectional communication with the control unit via thecommunication unit, such that the power adapter determines whether thereis a poor contact between the first charging interface and the secondcharging interface.

The controller receives a fourth instruction sent by the control unit.The fourth instruction is configured to query a current voltage of thebattery in the terminal. The controller sends a fourth reply instructionto the control unit, in which the fourth reply instruction is configuredto indicate the current voltage of the battery in the terminal, suchthat the control unit determines whether there is the poor contactbetween the first charging interface and the second charging interfaceaccording to an output voltage of the power adapter and the currentvoltage of the battery.

As an embodiment, the controller is configured to receive a fifthinstruction sent by the control unit. The fifth instruction isconfigured to indicate that there is the poor contact between the firstcharging interface and the second charging interface.

In order to initiate and adopt the second charging mode, the poweradapter may perform a fast charging communication procedure with theterminal, for example, by one or more handshakes, so as to realize thefast charging of battery. Referring to FIG. 10, the fast chargingcommunication procedure according to embodiments of the presentdisclosure and respective stages in the fast charging process will bedescribed in detail. It should be understood that, communication actionsor operations illustrated in FIG. 10 are merely exemplary. Otheroperations or various modifications of respective operations in FIG. 10can be implemented in embodiments of the present disclosure. Inaddition, respective stages in FIG. 10 may be executed in an orderdifferent from that illustrated in FIG. 10, and it is unnecessary toexecute all the operations illustrated in FIG. 10. It should be notedthat, a curve in FIG. 10 represents a variation trend of a peak value ora mean value of the charging current, rather than a curve of actualcharging current.

As illustrated in FIG. 10, the fast charging process may include thefollowing five stages.

Stage 1:

After being coupled to a power supply providing device, the terminal maydetect a type of the power supply providing device via the data wire D+and D−. When detecting that the power supply providing device is a poweradapter, the terminal may absorb current greater than a predeterminedcurrent threshold I2, such as 1. When the power adapter detects thatcurrent outputted by the power adapter is greater than or equal to I2within a predetermined time period (such as a continuous time periodT1), the power adapter determines that the terminal has completed therecognition of the type of the power supply providing device. The poweradapter initiates a handshake communication between the power adapterand the terminal, and sends an instruction 1 (corresponding to theabove-mentioned first instruction) to query the terminal whether tostart the second charging mode (or flash charging).

When receiving a reply instruction indicating that the terminaldisagrees to start the second charging mode from the terminal, the poweradapter detects the output current of the power adapter again. When theoutput current of the power adapter is still greater than or equal to I2within a predetermined continuous time period (such as a continuous timeperiod T1), the power adapter initiates a request again to query theterminal whether to start the second charging model. The above actionsin stage 1 are repeated, until the terminal replies that it agrees tostart the second charging mode or the output current of the poweradapter is no longer greater than or equal to I2.

After the terminal agrees to start the second charging mode, the fastcharging process is initiated, and the fast charging communicationprocedure goes into stage 2.

Stage 2:

For the voltage with the steamed bun waveform outputted by the poweradapter, there may be several levels. The power adapter sends aninstruction 2 (corresponding to the above-mentioned second instruction)to the terminal to query the terminal whether the output voltage of thepower adapter matches to the current voltage of the battery (or whetherthe output voltage of the power adapter is suitable, i.e., suitable forthe charging voltage in the second charging mode), i.e., whether theoutput voltage of the power adapter meets the charging requirement.

The terminal replies that the output voltage of the power adapter ishigher, lower or suitable. When the power adapter receives a feedbackindicating that the output voltage of the power adapter is lower orhigher from the terminal, the control unit adjusts the output voltage ofthe power adapter by one level by adjusting the duty ratio of the PWMsignal, and sends the instruction 2 to the terminal again to query theterminal whether the output voltage of the power adapter matches.

The above actions in stage 2 are repeated, until the terminal replies tothe power adapter that the output voltage of the power adapter is at amatching level. And then the fast charging communication procedure goesinto stage 3.

Stage 3:

After the power adapter receives the feedback indicating that the outputvoltage of the power adapter matches from the terminal, the poweradapter sends an instruction 3 (corresponding to the above-mentionedthird instruction) to the terminal to query the maximum charging currentsupported by the terminal. The terminal returns to the power adapter themaximum charging current supported by itself, and then the fast chargingcommunication procedure goes into stage 4.

Stage 4:

After receiving a feedback indicating the maximum charging currentsupported by the terminal from the terminal, the power adapter may setan output current reference value. The control unit 107 adjusts the dutyratio of the PWM signal according to the output current reference value,such that the output current of the power adapter meets the chargingcurrent requirement of the terminal, and the fast charging communicationprocedure goes into constant current stage. The constant current stagemeans that the peak value or mean value of the output current of thepower adapter basically remains unchanged (which means that thevariation amplitude of the peak value or mean value of the outputcurrent is very small, for example within a range of 5% of the peakvalue or mean value of the output current), namely, the peak value ofthe current with the third pulsating waveform keeps constant in eachperiod.

Stage 5:

When the fast charging communication procedure goes into the constantcurrent stage, the power adapter sends an instruction 4 (correspondingto the above-mentioned fourth instruction) at intervals to query thecurrent voltage of battery in the terminal. The terminal may feedback tothe power adapter the current voltage of the battery, and the poweradapter may determine according to the feedback of the current voltageof the battery whether there is a poor USB contact (i.e., a poor contactbetween the first charging interface and the second charging interface)and whether it is necessary to decrease the charging current value ofthe terminal. When the power adapter determines that there is the poorUSB contact, the power adapter sends an instruction 5 (corresponding tothe above-mentioned fifth instruction), and then the power adapter isreset, such that the fast charging communication procedure goes intostage 1 again.

In some embodiments of the present disclosure, in stage 1, when theterminal replies to the instruction 1, data corresponding to theinstruction 1 may carry data (or information) on the path impedance ofthe terminal. The data on the path impedance of the terminal may be usedin stage 5 to determine whether there is the poor USB contact.

In some embodiments of the present disclosure, in stage 2, the timeperiod from when the terminal agrees to start the second charging modeto when the power adapter adjusts the voltage to a suitable value may belimited in a certain range. If the time period exceeds a predeterminedrange, the terminal may determine that there is an exception request,thus a quick reset is performed.

In some embodiments of the present disclosure, in stage 2, the terminalmay give a feedback indicating that the output voltage of the poweradapter is suitable/matches to the power adapter when the output voltageof the power adapter is adjusted to a value higher than the currentvoltage of the battery by ΔV (ΔV is about 200-500 mV). When the terminalgives a feedback indicating that the output voltage of the power adapteris not suitable (higher or lower) to the power adapter, the control unit107 adjusts the duty ratio of the PWM signal according to the voltagesampling value, so as to adjust the output voltage of the power adapter.

In some embodiments of the present disclosure, in stage 4, the adjustingspeed of the output current value of the power adapter may be controlledto be in a certain range, thus avoiding an abnormal interruption of thefast charging due to the too fast adjusting speed.

In some embodiments of the present disclosure, in stage 5, the variationamplitude of the output current value of the power adapter may becontrolled to be within 5%, i.e., stage 5 may be regarded as theconstant current stage.

In some embodiments of the present disclosure, in stage 5, the poweradapter monitors the impedance of a charging loop in real time, i.e.,the power adapter monitors the impedance of the whole charging loop bymeasuring the output voltage of the power adapter, the charging currentand the read-out voltage of the battery in the terminal. When theimpedance of the charging loop>the path impedance of the terminal+theimpedance of the fast charging data wire, it may be considered thatthere is the poor USB contact, and thus a fast charging reset isperformed.

In some embodiments of the present disclosure, after the second chargingmode is started, a time interval of communications between the poweradapter and the terminal may be controlled to be in a certain range,such that the fast charging reset can be avoided.

In some embodiments of the present disclosure, the termination of thesecond charging mode (or the fast charging process) may be a recoverabletermination or an unrecoverable termination.

For example, when the terminal detects that the battery is fully chargedor there is the poor USB contact, the fast charging is stopped andreset, and the fast charging communication procedure goes into stage 1.When the terminal disagrees to start the second charging mode, the fastcharging communication procedure would not go into stage 2, thus thetermination of the fast charging process may be considered as anunrecoverable termination.

For another example, when an exception occurs in the communicationbetween the terminal and the power adapter, the fast charging is stoppedand reset, and the fast charging communication procedure goes intostage 1. After requirements for stage 1 are met, the terminal agrees tostart the second charging mode to recover the fast charging process,thus the termination of the fast charging process may be considered as arecoverable termination.

For another example, when the terminal detects an exception occurring inthe battery, the fast charging is stopped and reset, and the fastcharging communication procedure goes into stage 1. After the fastcharging communication procedure goes into stage 1, the terminaldisagrees to start the second charging mode. Till the battery returns tonormal and the requirements for stage 1 are met, the terminal agrees tostart the fast charging to recover the fast charging process. Thus, thetermination of fast charging process may be considered as a recoverabletermination.

It should be noted that, communication actions or operations illustratedin FIG. 10 are merely exemplary. For example, in stage 1, after theterminal is coupled to the power adapter, the handshake communicationbetween the terminal and the power adapter may be initiated by theterminal. In other words, the terminal sends an instruction 1 to querythe power adapter whether to start the second charging mode (or flashcharging). When receiving a reply instruction indicating that the poweradapter agrees to start the second charging mode from the power adapter,the terminal starts the fast charging process.

It should be noted that, communication actions or operations illustratedin FIG. 10 are merely exemplary. For example, after stage 5, there is aconstant voltage charging stage. In other words, in stage 5, theterminal may feedback the current voltage of the battery in the terminalto the power adapter. As the voltage of the battery increasescontinuously, the charging goes into the constant voltage charging stagewhen the current voltage of the battery reaches a constant voltagecharging voltage threshold. The control unit 107 adjusts the duty ratioof the PWM signal according to the voltage reference value (i.e., theconstant voltage charging voltage threshold), such that the outputvoltage of the power adapter meets the charging voltage requirement ofthe terminal, i.e., the output voltage of the power adapter basicallychanges at a constant rate. During the constant voltage charging stage,the charging current decreases gradually. When the current reduces to acertain threshold, the charging is stopped and it is illustrated thatthe battery is fully charged. The constant voltage charging refers tothat the peak voltage with the third pulsating waveform basically keepsconstant.

It should be noted that, in embodiments of the present disclosure,acquiring output voltage of the power adapter means that the peak valueor mean value of voltage with the third pulsating waveform is acquired.Acquiring output current of the power adapter means that the peak valueor mean value of current with the third pulsating waveform is acquired.

In an embodiment of the present disclosure, as illustrated in FIG. 12,the power adapter 1 further includes a controllable switch 108 and afiltering unit 109 in series. The controllable switch 108 and thefiltering unit 109 in series are coupled to the first output end of thesecond rectifier 104. The control unit 107 is further configured tocontrol the controllable switch 108 to switch on when determining thecharging mode as the first charging mode, and to control thecontrollable switch 108 to switch off when determining the charging modeas the second charging mode. The output end of the second rectifier 104is further coupled to one or more groups of small capacitors inparallel, which can not only realize a noise reduction, but also reducethe occurrence of surge phenomenon. The output end of the secondrectifier 104 is further coupled to an LC filtering circuit or π typefiltering circuit, so as to filter out pulsating interference. Asillustrated in FIG. 12, the output end of the second rectifier 104 iscoupled to an LC filtering circuit. It should be noted that, allcapacitors in the LC filtering circuit or the π type filtering circuitare small capacitors, which occupy small space.

The filtering unit 109 includes a filtering capacitor, which supports astandard charging of 5V corresponding to the first charging mode. Thecontrollable switch 108 may be formed of a semiconductor switch elementsuch as a MOS transistor. When the power adapter charges the battery inthe terminal in the first charging mode (or called as standardcharging), the control unit 107 controls the controllable switch 108 toswitch on so as to incorporate the filtering unit 109 into the circuit,such that a filtering can be performed on the output of the secondrectifier 104. In this way, the direct charging technology iscompatible, i.e., the direct current is applied to the battery in theterminal so as to realize direct current charging of the battery. Forexample, in general, the filtering unit includes an electrolyticcondenser and a common capacitor such as a small capacitor supportingstandard charging of 5V (for example, a solid-state capacitor) inparallel. Since the electrolytic condenser occupies a bigger volume, inorder to reduce the size of the power adapter, the electrolyticcondenser may be removed from the power adapter and only one capacitorwith low capacitance is left. When the first charging mode is adopted, abranch where the small capacitor is located is switched on, and thecurrent is filtered to realize a stable output with low power forperforming a direct current charging on the battery. When the secondcharging mode is adopted, a branch where the small capacitor is locatedis switched off, and the output of the second rectifier 104 directlyapply the voltage/current with pulsating waveform without filtering tothe battery, so as to realize a fast charging of the battery.

According to an embodiment of the present disclosure, the control unit107 is further configured to obtain the charging current and/or thecharging voltage corresponding to the second charging mode according tothe status information of the terminal and to adjust the duty ratio ofthe control signal such as the PWM signal according to the chargingcurrent and/or the charging voltage corresponding to the second chargingmode, when determining the charging mode as the second charging mode. Inother words, when determining the current charging mode as the secondcharging mode, the control unit 107 obtains the charging current and/orthe charging voltage corresponding to the second charging mode accordingto the obtained status information of the terminal such as the voltage,the electric quantity and the temperature of the battery, runningparameters of the terminal and power consumption information ofapplications running on the terminal, and adjusts the duty ratio of thecontrol signal according to the charging current and/or the chargingvoltage, such that the output of the power adapter meets the chargingrequirement, thus realizing the fast charging of the battery.

The status information of the terminal includes the temperature of theterminal. When the temperature of the battery is greater than a firstpredetermined temperature threshold, or the temperature of the batteryis less than a second predetermined temperature threshold, if thecurrent charging mode is the second charging mode, the second chargingmode is switched to the first charging mode. The first predeterminedtemperature threshold is greater than the second predeterminedtemperature threshold. In other words, when the temperature of thebattery is too low (for example, corresponding to less than the secondpredetermined temperature threshold) or too high (for example,corresponding to greater than the first predetermined temperaturethreshold), it is unsuitable to perform the fast charging, such that itneeds to switch from the second charging mode to the first chargingmode. In embodiments of the present disclosure, the first predeterminedtemperature threshold and the second predetermined temperature thresholdcan be set according to actual situations, or can be written into thestorage of the control unit (such as the MCU of the power adapter).

In an embodiment of the present disclosure, the control unit 107 isfurther configured to control the switch unit 102 to switch off when thetemperature of the battery is greater than a predetermined hightemperature protection threshold. Namely, when the temperature of thebattery exceeds the high temperature protection threshold, the controlunit 107 needs to apply a high temperature protection strategy tocontrol the switch unit 102 to switch off, such that the power adapterstops charging the battery, thus realizing the high protection of thebattery and improving the safety of charging. The high temperatureprotection threshold may be different from or the same to the firsttemperature threshold. In an embodiment, the high temperature protectionthreshold is greater than the first temperature threshold.

In another embodiment of the present disclosure, the controller isfurther configured to obtain the temperature of the battery, and tocontrol the charging control switch to switch off (i.e., the chargingcontrol switch can be switched off at the terminal side) when thetemperature of the battery is greater than the predetermined hightemperature protection threshold, so as to stop the charging process ofthe battery and to ensure the safety of charging.

Moreover, in an embodiment of the present disclosure, the control unitis further configured to obtain a temperature of the first charginginterface, and to control the switch unit to switch off when thetemperature of the first charging interface is greater than apredetermined protection temperature. In other words, when thetemperature of the charging interface exceeds a certain temperature, thecontrol unit 107 needs to apply the high temperature protection strategyto control the switch unit 102 to switch off, such that the poweradapter stops charging the battery, thus realizing the high protectionof the battery and improving the safety of charging.

Certainly, in another embodiment of the present disclosure, thecontroller obtains the temperature of the first charging interface byperforming the bidirectional communication with the control unit. Whenthe temperature of the first charging interface is greater than thepredetermined protection temperature, the controller controls thecharging control switch (referring to FIG. 18 and FIG. 19) to switchoff, i.e., switches off the charging control switch at the terminalside, so as to stop the charging process of the battery, thus ensuringthe safety of charging.

In detail, in an embodiment of the present disclosure, as illustrated inFIG. 13, the power adapter 1 further includes a driving unit 110 such asa MOSFET driver. The driving unit 110 is coupled between the switch unit102 and the control unit 107. The driving unit 110 is configured todrive the switch unit 102 to switch on or off according to the controlsignal. Certainly, it should be noted, in other embodiments of thepresent disclosure, the driving unit 110 may also be integrated in thecontrol unit 107.

Further, as illustrated in FIG. 13, the power adapter 1 further includesan isolation unit 111. The isolation unit 111 is coupled between thedriving unit 110 and the control unit 107, to prevent high voltages fromaffecting the control unit 107 at the secondary side of the transformer103. The isolation unit 111 may be implemented in an optical isolationmanner, or in other isolation manners. By setting the isolation unit111, the control unit 107 may be disposed at the secondary side of thepower adapter 1 (or the secondary winding side of the transformer 103),such that it is convenient to communicate with the terminal 2, and thespace design of the power adapter 1 becomes easier and simpler.

Certainly, it should be understood that, in other embodiments of thepresent disclosure, both the control unit 107 and the driving unit 110can be disposed as the primary side, in this way, the isolation unit 111can be disposed between the control unit 107 and the sampling unit 106Further, it should be noted that, in embodiments of the presentdisclosure, when the control unit 107 is disposed at the secondary side,an isolation unit 111 is required, and the isolation unit 111 may beintegrated in the control unit 107. In other words, when the signal istransmitted from the primary side to the secondary side or from thesecondary side to the primary side, an isolation unit is required toprevent high voltages from affecting the control unit 107 at thesecondary side of the transformer 103.

In an embodiment of the present disclosure, as illustrated in FIG. 14,the power adapter 1 further includes an auxiliary winding and a powersupply unit 112. The auxiliary winding generates a fourth voltage with afourth pulsating waveform according to the modulated first voltage. Thepower supply unit 112 is coupled to the auxiliary winding. The powersupply unit 112 (for example, including a filtering voltage regulatormodule, a voltage converting module and the like) is configured toconvert the fourth voltage with the fourth pulsating waveform and outputa direct current, and to supply power to the driving unit 110 and/or thecontrol unit 107 respectively. The power supply unit 112 may be formedof a small filtering capacitor, a voltage regulator chip or otherelements, performs a process and conversation on the fourth voltage withthe fourth pulsating waveform and outputs the low voltage direct currentsuch as 3.3V, 5V or the like.

In other words, the power supply of the driving unit 110 can be obtainedby performing a voltage conversation on the fourth voltage with thefourth pulsating waveform by the power supply unit 112. When the controlunit 107 is disposed at the primary side, the power supply of thecontrol unit 107 can also be obtained by performing a voltageconversation on the fourth voltage with the fourth pulsating waveform bythe power supply unit 112. As illustrated in FIG. 14, when the controlunit 107 is disposed at the primary side, the power supply unit 112provides two lines of direct current outputs, so as to supply power tothe driving unit 110 and the control unit 107 respectively. An opticalisolation unit 111 is arranged between the control unit 107 and thesampling unit 106 to prevent high voltages from affecting the controlunit 107 at the secondary side of the transformer 103.

When the control unit 107 is disposed at the primary side and integratedwith the driving unit 110, the power supply unit 112 supplies power tothe control unit 107 only. When the control unit 107 is disposed at thesecondary side and the driving unit 110 is disposed at the primary side,the power supply unit 112 supplies power to the driving unit 110 only.The power supply to the control unit 107 is realized by the secondaryside, for example, a power supply unit converts the third voltage withthe third pulsating waveform outputted by the second rectifier 104 todirect current to supply power to the control unit 107.

Moreover, in embodiments of the present disclosure, several smallcapacitors are coupled in parallel to the output end of first rectifier101 for filtering. Or the output end of the first rectifier 101 iscoupled to an LC filtering circuit.

In another embodiment of the present disclosure, as illustrated in FIG.15, the power adapter 1 further includes a first voltage detecting unit113. The first voltage detecting unit 113 is coupled to the auxiliarywinding and the control unit 107 respectively. The first voltagedetecting unit 113 is configured to detect the fourth voltage togenerate a voltage detecting value. The control unit 107 is furtherconfigured to adjust the duty ratio of the control signal according tothe voltage detecting value.

In other words, the control unit 107 may reflect the voltage outputtedby the second rectifier 104 with the voltage outputted by the secondarywinding and detected by the first voltage detecting unit 113, and thenadjusts the duty ratio of the control signal according to the voltagedetecting value, such that the output of the second rectifier 104 meetsthe charging requirement of the battery.

In detail, in an embodiment of the present disclosure, as illustrated inFIG. 16, the sampling unit 106 includes a first current sampling circuit1061 and a first voltage sampling circuit 1062. The first currentsampling circuit 1061 is configured to sample the current outputted bythe second rectifier 104 to obtain the current sampling value. The firstvoltage sampling circuit 1062 is configured to sample the voltageoutputted by the second rectifier 104 to obtain the voltage samplingvalue.

In an embodiment of the present disclosure, the first current samplingcircuit 1061 can sample the current outputted by the second rectifier104 by sampling voltage on a resistor (current detection resistor) at afirst output end of the second rectifier 104. The first voltage samplingcircuit 1062 can sample the voltage outputted by the second rectifier104 by sampling the voltage cross the first output end and a secondoutput end of the second rectifier 104.

Moreover, in an embodiment of the present disclosure, as illustrated inFIG. 16, the first voltage sampling circuit 1062 includes a peak voltagesampling and holding unit, a cross-zero sampling unit, a leakage unitand an AD sampling unit. The peak voltage sampling and holding unit isconfigured to sample and hold a peak voltage of the third voltage. Thecross-zero sampling unit is configured to sample a zero crossing pointof the third voltage. The leakage unit is configured to perform aleakage on the peak voltage sampling and holding unit at the zerocrossing point. The AD sampling unit is configured to sample the peakvoltage in the peak voltage sampling and holding unit so as to obtainthe voltage sampling value.

By providing with the peak voltage sampling and holding unit, thecross-zero sampling unit, the leakage unit and the AD sampling unit inthe first voltage sampling circuit 1062, the voltage outputted by thesecond rectifier 104 may be sampled accurately, and it can be guaranteedthat the voltage sampling value keeps synchronous with the firstvoltage, i.e., the phase and variation trend of magnitude of the voltagesampling value are consistent with those of the first voltagerespectively.

According to an embodiment of the present disclosure, as illustrated inFIG. 17, the power adapter 1 further includes a second voltage samplingcircuit 114. The second voltage sampling circuit 114 is configured tosample the first voltage with the first pulsating waveform. The secondvoltage sampling circuit 114 is coupled to the control unit 107. Whenthe voltage value sampled by the second voltage sampling circuit 114 isgreater than a first predetermined voltage value, the control unit 104controls the switch unit 102 to switch on for a predetermined timeperiod, for performing a discharge on the surge voltage, spike voltagein the first voltage with the first pulsating waveform.

As illustrated in FIG. 17, the second voltage sampling circuit 114 canbe coupled to the first output end and the second output end of thefirst rectifier 101, so as to sample the first voltage with the firstpulsating waveform. The control unit 107 performs a determination on thevoltage value sampled by the second voltage sampling circuit 114. Whenthe voltage value sampled by the second voltage sampling circuit 114 isgreater than the first predetermined voltage value, it indicates thatthe power adapter 1 is disturbed by lightning stroke and the surgevoltage is generated. At this time, a leakage is required for the surgevoltage to ensure the safety and reliability of charging. The controlunit 107 controls the switch unit 102 to switch on for a certain timeperiod, to form a leakage circuit, such that the leakage is performed onthe surge voltage caused by lightning stroke, thus avoiding thedisturbance caused by the lightning stroke when the power adaptercharges the terminal, and effectively improving the safety andreliability of the charging of the terminal. The first predeterminedvoltage value may be determined according to actual situations.

In an embodiment of the present disclosure, during a process that thepower adapter 1 charges the battery of the terminal 2, the control unit107 is further configured to control the switch unit 102 to switch offwhen the voltage sampled by the sampling unit 106 is greater than asecond predetermined voltage value. Namely, the control unit 107 furtherperforms a determination on the voltage sampled by the sampling unit106. When the voltage sampled by the sampling unit 106 is greater thanthe second predetermined voltage value, it indicates that the voltageoutputted by the power adapter 1 is too high. At this time, the controlunit 107 controls the power adapter 1 to stop charging the battery 202of the terminal 2 by controlling the switch unit 102 to switch off. Inother words, the control unit 107 realizes the over-voltage protectionof the power adapter by controlling the switch unit 102 to switch off,thus ensuring the safety of charging.

Certainly, in an embodiment of the present disclosure, the controller204 obtains the voltage sampled by the sampling unit 106 (FIG. 18 andFIG. 19) by performing a bidirectional communication with the controlunit 107, and controls the charging control switch 203 to switch offwhen the voltage sampled by the sampling unit 106 is greater than thesecond predetermined voltage value. Namely, the charging control switch203 is controlled to switch off at the terminal 2 side, so as to stopthe charging process of the battery 202, such that the safety ofcharging can be ensured.

Further, the control unit 107 is further configured to control theswitch unit 102 to switch off when the current sampled by the samplingunit 106 is greater than a predetermined current value. In other words,the control unit 107 further performs a determination on the currentsampled by the sampling unit 106. When the current sampled by thesampling unit 106 is greater than the predetermined current value, itindicates that the current outputted by the power adapter 1 is too high.At this time, the control unit 107 controls the power adapter 1 to stopcharging the terminal by controlling the switch unit 102 to switch off.In other words, the control unit 107 realizes the over-currentprotection of the power adapter 1 by controlling the switch unit 102 toswitch off, thus ensuring the safety of charging.

Similarly, the controller 204 obtains the current sampled by thesampling unit 106 (FIG. 18 and FIG. 19) by performing the bidirectionalcommunication with the control unit 107, and controls to switch off thecharging control switch 203 when the current sampled by the samplingunit 106 is greater than the predetermined current value. In otherwords, the charging control switch 203 is controlled to be switched offat the terminal 2 side, so as to stop the charging process of thebattery 202, thus ensuring the safety of charging.

The second predetermined voltage value and the predetermined currentvalue may be set or written into a storage of the control unit (forexample, in the control unit 107 of the power adapter 1, such as themicroprogrammed control unit (MCU)) according to actual situations.

In embodiments of the present disclosure, the terminal may be a mobileterminal, such as a mobile phone, a mobile power supply such as a powerbank, a multimedia player, a notebook PC, a wearable device or the like.

With the charging system for a terminal according to embodiments of thepresent disclosure, the power adapter is controlled to output the thirdvoltage with the third pulsating waveform, and the third voltage withthe third pulsating waveform outputted by the power adapter is directlyapplied to the battery of the terminal, thus realizing fast charging tothe battery directly by the pulsating output voltage/current. Incontrast to the conventional constant voltage and constant current, amagnitude of the pulsating output voltage/current changes periodically,such that a lithium precipitation of the lithium battery may be reduced,the service life of the battery may be improved, and a probability andintensity of arc discharge of a contact of a charging interface may bereduced, the service life of the charging interface may be prolonged,and it is beneficial to reduce polarization effect of the battery,improve charging speed, and decrease heat emitted by the battery, thusensuring a reliability and safety of the terminal during the charging.Moreover, since the power adapter outputs the voltage with the pulsatingwaveform, it is unnecessary to provide an electrolytic condenser in thepower adapter, which not only realizes simplification andminiaturization of the power adapter, but also decreases cost greatly.

Embodiments of the present disclosure further provide a power adapter.The power adapter includes a first rectifier, a switch unit, atransformer, a second rectifier, a first charging interface, a samplingunit, and a control unit. The first rectifier is configured to rectifyan input alternating current and output a first voltage with a firstpulsating waveform. The switch unit is configured to modulate the firstvoltage according to a control signal and output a modulated firstvoltage. The transformer is configured to output a second voltage with asecond pulsating waveform according to the modulated first voltage. Thesecond rectifier is configured to rectify the second voltage to output athird voltage with a third pulsating waveform. The first charginginterface is coupled to the second rectifier, and configured to applythe third voltage to a battery in a terminal via a second charginginterface of the terminal when the first charging interface is coupledto the second charging interface, in which the second charging interfaceis coupled to the battery. The sampling unit is configured to samplevoltage and/or current outputted by the second rectifier to obtain avoltage sampling value and/or a current sampling value. The control unitis coupled to the sampling unit and the switch unit respectively, andconfigured to adjust a duty ratio of the control signal according to thecurrent sampling value and/or the voltage sampling value, such that thethird voltage meets a charging requirement of the terminal.

With the power adapter according to embodiments of the presentdisclosure, the third voltage with the third pulsating waveform isoutputted via the first charging interface, and the third voltage isdirectly applied to the battery of the terminal via the second charginginterface of the terminal, thus realizing fast charging to the batterydirectly by the pulsating output voltage/current. In contrast to theconventional constant voltage and constant current, a magnitude of thepulsating output voltage/current changes periodically, such that alithium precipitation of the lithium battery may be reduced, the servicelife of the battery may be improved, and a probability and intensity ofarc discharge of a contact of a charging interface may be reduced, theservice life of the charging interface may be prolonged, and it isbeneficial to reduce polarization effect of the battery, improvecharging speed, and decrease heat emitted by the battery, thus ensuringa reliability and safety of the terminal during the charging. Moreover,since the voltage with the pulsating waveform is output, it isunnecessary to provide an electrolytic condenser, which not onlyrealizes simplification and miniaturization of the power adapter, butalso decreases cost greatly.

FIG. 20 is a flow chart of a charging method for a terminal according toembodiments of the present disclosure. As illustrated in FIG. 20, thecharging method for a terminal includes the followings.

At block S1, when a first charging interface of a power adapter iscoupled to a second charging interface of a terminal, a firstrectification is performed on alternating current inputted into thepower adapter to output a first voltage with a first pulsating waveform.

In other words, a first rectifier in the power adapter rectifies theinputted alternating current (i.e., the mains supply, such asalternating current of 220V, 50 Hz or 60 Hz) and outputs the firstvoltage (for example, 100 Hz or 120 Hz) with the first pulsatingwaveform, such as a voltage with a steamed bun waveform.

At block S2, the first voltage with the first pulsating waveform ismodulated by a switch unit, and then is converted by a transformer toobtain a second voltage with a second pulsating waveform.

The switch unit may be formed of a MOS transistor. A PWM control isperformed on the MOS transistor to perform a chopping modulation on thevoltage with the steamed bun waveform. And then, the modulated firstvoltage is coupled to a secondary side by the transformer, such that thesecondary winding outputs the second voltage with the second pulsatingwaveform.

In an embodiment of the present disclosure, a high-frequency transformeris used for conversion, such that the size of the transformer is small,thus realizing miniaturization of the power adapter with high-power.

At block S3, a second rectification is performed on the second voltagewith the second pulsating waveform to output a third voltage with athird pulsating waveform. The third voltage with the third pulsatingwaveform may be applied to a battery of the terminal via the secondcharging interface, so as to charge the battery of the terminal.

In an embodiment of the present disclosure, the second rectification isperformed by a second rectifier on the second voltage with the secondpulsating waveform. The second rectifier may be formed of a diode or aMOS transistor, and can realize a secondary synchronous rectification,such that the third pulsating waveform keeps synchronous with thewaveform of the modulated first voltage.

At block S4, the voltage and/or current after the second rectificationis sampled to obtain a voltage sampling value and/or a current samplingvalue.

At block S5, a duty ratio of a control signal for controlling the switchunit is adjusted according to the voltage sampling value and/or thecurrent sampling value, such that the third voltage with the thirdpulsating waveform meets a charging requirement.

It should be noted that, the third voltage with the third pulsatingwaveform meeting the charging requirement means that, the third voltageand current with the third pulsating waveform need to meet the chargingvoltage and charging current when the battery is charged. In otherwords, the duty ratio of the control signal (such as a PWM signal) isadjusted according to the voltage and/or current outputted by the poweradapter, so as to adjust the output of the power adapter in real timeand realize a closed-loop adjusting control, such that the third voltagewith the third pulsating waveform meets the charging requirement of theterminal, thus ensuring the stable and safe charging of the battery. Indetail, a waveform of a charging voltage outputted to a battery isillustrated in FIG. 7, in which the waveform of the charging voltage isadjusted according to the duty ratio of the PWM signal. A waveform of acharging current outputted to a battery is illustrated in FIG. 8, inwhich the waveform of the charging current is adjusted according to theduty ratio of the PWM signal.

In an embodiment of the present disclosure, by controlling the switchunit, a chopping modulation is directly performed on the first voltagewith the first pulsating waveform i.e., the steamed bun waveform after afull-bridge rectification, and then a modulated voltage is sent to thehigh-frequency transformer and is coupled from the primary side to thesecondary side via the high-frequency transformer, and then is changedback to the voltage/current with the steamed bun waveform after asynchronous rectification. The voltage/current with the steamed bunwaveform is directly transmitted to the battery so as to realize fastcharging to the battery. The magnitude of the voltage with the steamedbun waveform may be adjusted according to the duty ratio of the PWMsignal, such that the output of the power adapter may meet the chargingrequirement of the battery. It can be seen from that, electrolyticcondensers at the primary side and the secondary side in the poweradapter can be removed, and the battery can be directly charged via thevoltage with the steamed bun waveform, such that a size of the poweradapter may be reduced, thus realizing miniaturization of the poweradapter, and decreasing cost greatly.

According to an embodiment of the present disclosure, a frequency of thecontrol signal is adjusted according to the voltage sampling valueand/or the current sampling value. That is, the output of the PWM signalto the switch unit is controlled to maintain for a continuous timeperiod, and then stop for a predetermined time period and then restart.In this way, the voltage applied to the battery is intermittent, thusrealizing the intermittent charging of the battery, which avoids asafety hazard caused by heating phenomenon occurring when the battery ischarged continuously and improves the reliability and safety of thecharging to the battery. The control signal outputted to the switch unitis illustrated in FIG. 9.

Further, the above charging method for a terminal includes: performing acommunication with the terminal via the first charging interface toobtain status information of the terminal, and adjusting the duty ratioof the control signal according to the status information of theterminal, the voltage sampling value and/or current sampling value.

In other words, when the second charging interface is coupled to thefirst charging interface, the power adapter and the terminal may sendcommunication query instructions to each other, and a communicationconnection can be established between the power adapter and the terminalafter corresponding reply instructions are received, such that the poweradapter can obtain the status information of the terminal, negotiateswith the terminal about the charging mode and the charging parameter(such as the charging current, the charging voltage) and controls thecharging process.

According to an embodiment of the present disclosure, a fourth voltagewith a fourth pulsating waveform can be generated by a conversion of thetransformer, and the fourth voltage with the fourth pulsating waveformcan be detected to generate a voltage detecting value, and the dutyratio of the control signal can be adjusted according to the voltagedetecting value.

In detail, the transformer can be provided with an auxiliary winding.The auxiliary winding can generate the fourth voltage with the fourthpulsating waveform according to the modulated first voltage. The outputvoltage of the power adapter can be reflected by detecting the fourthvoltage with the fourth pulsating waveform, and the duty ratio of thecontrol signal can be adjusted according to the voltage detecting value,such that the output of the power adapter meets the charging requirementof the battery.

In an embodiment of the present disclosure, sampling the voltage afterthe second rectification to obtain the voltage sampling value including:sampling and holding a peak value of the voltage after the secondrectification, and sampling a zero crossing point of the voltage afterthe second rectification; performing a leakage on a peak voltagesampling and holding unit configured for sampling and holding the peakvoltage at the zero crossing point; and sampling the peak voltage in thepeak voltage sampling and holding unit so as to obtain the voltagesampling value. In this way, an accurate sampling can be performed onthe voltage outputted by the power adapter, and it can be guaranteedthat the voltage sampling value keeps synchronous with the first voltagewith the first pulsating waveform, i.e., the phase and variation trendof magnitude of the voltage sampling value are consistent with those ofthe first voltage respectively.

Further, in an embodiment of the present disclosure, the above chargingmethod for a terminal includes: sampling the first voltage with thefirst pulsating waveform, and controlling the switch unit to switch onfor a predetermined time period for performing a discharge on surgevoltage in the first voltage with the first pulsating waveform when asampled voltage value is greater than a first predetermined voltagevalue.

The first voltage with the first pulsating waveform is sampled so as todetermine the sampled voltage value. When the sampled voltage value isgreater than the first predetermined voltage value, it indicates thatthe power adapter is disturbed by lightning stroke and the surge voltageis generated. At this time, a leakage is required for the surge voltageto ensure the safety and reliability of charging. It is required tocontrol the switch unit to switch on for a certain time period, to forma leakage circuit, such that the leakage is performed on the surgevoltage caused by lightning stroke, thus avoiding the disturbance causedby the lightning stroke when the power adapter charges the terminal, andeffectively improving the safety and reliability of the charging of theterminal. The first predetermined voltage value may be determinedaccording to actual situations.

According an embodiment of the present disclosure, a communication withthe terminal is performed via the first charging interface to determinethe charging mode. When the charging mode is determined as the secondcharging mode, the charging current and/or charging voltagecorresponding to the second charging mode can be obtained according tothe status information of the terminal, so as to adjust the duty ratioof the control signal according to the charging current and/or chargingvoltage corresponding to the second charging mode. The charging modeincludes the second charging mode and the first charging mode.

In other words, when the current charging mode is determined as thesecond charging mode, the charging current and/or charging voltagecorresponding to the second charging mode can be obtained according tothe status information of the terminal, such as the voltage, electricquantity, temperature of the battery, running parameters of the terminaland power consumption information of applications running on theterminal or the like. And the duty ratio of the control signal isadjusted according to the obtained charging current and/or chargingvoltage, such that the output of the power adapter meets the chargingrequirement, thus realizing the fast charging of the terminal.

The status information of the terminal includes the temperature of thebattery. When the temperature of the battery is greater than a firstpredetermined temperature threshold, or the temperature of the batteryis less than a second predetermined temperature threshold, if thecurrent charging mode is the second charging mode, the second chargingmode is switched to the first charging mode. The first predeterminedtemperature threshold is greater than the second predeterminedtemperature threshold. In other words, when the temperature of thebattery is too low (for example, corresponding to less than the secondpredetermined temperature threshold) or too high (for example,corresponding to greater than the first predetermined temperaturethreshold), it is unsuitable to perform the fast charging, such that itneeds to switch from the second charging mode to the first chargingmode. In embodiments of the present disclosure, the first predeterminedtemperature threshold and the second predetermined temperature thresholdcan be set according to actual situations.

In an embodiment of the present disclosure, the switch unit iscontrolled to switch off when the temperature of the battery is greaterthan a predetermined high temperature protection threshold. Namely, whenthe temperature of the battery exceeds the high temperature protectionthreshold, it needs to apply a high temperature protection strategy tocontrol the switch unit to switch off, such that the power adapter stopscharging the battery, thus realizing the high protection of the batteryand improving the safety of charging. The high temperature protectionthreshold may be different from or the same to the first temperaturethreshold. In an embodiment, the high temperature protection thresholdis greater than the first temperature threshold.

In another embodiment of the present disclosure, the terminal furtherobtains the temperature of the battery, and controls to stop chargingthe battery (for example by controlling a charging control switch toswitch off at the terminal side) when the temperature of the battery isgreater than the predetermined high temperature protection threshold, soas to stop the charging process of the battery and to ensure the safetyof charging.

Moreover, in an embodiment of the present disclosure, the chargingmethod for a terminal further includes: obtaining a temperature of thefirst charging interface, and controlling the switch unit to switch offwhen the temperature of the first charging interface is greater than apredetermined protection temperature. In other words, when thetemperature of the charging interface exceeds a certain temperature, thecontrol unit needs to apply the high temperature protection strategy tocontrol the switch unit to switch off, such that the power adapter stopscharging the battery, thus realizing the high protection of the batteryand improving the safety of charging.

Certainly, in another embodiment of the present disclosure, the terminalobtains the temperature of the first charging interface by performingthe bidirectional communication with the power adapter via the secondcharging interface. When the temperature of the first charging interfaceis greater than the predetermined protection temperature, the terminalcontrols the charging control switch to switch off, i.e., the chargingcontrol switch can be switched off at the terminal side, so as to stopthe charging process of the battery, thus ensuring the safety ofcharging.

During a process that the power adapter charges to the terminal, theswitch unit is controlled to switch off when the voltage sampling valueis greater than a second predetermined voltage value. Namely, adetermination is performed on the voltage sampling value during theprocess that the power adapter charges the terminal. When the voltagesampling value is greater than the second predetermined voltage value,it indicates that the voltage outputted by the power adapter is toohigh. At this time, the power adapter is controlled to stop charging theterminal by controlling the switch unit to switch off. In other words,the over-voltage protection of the power adapter is realized bycontrolling the switch unit to switch off, thus ensuring the safety ofcharging.

Certainly, in an embodiment of the present disclosure, the terminalobtains the voltage sampling value by performing a bidirectionalcommunication with the power adapter via the second charging interface,and controls to stop charging the battery when the voltage samplingvalue is greater than the second predetermined voltage value. Namely,the charging control switch is controlled to switch off at the terminalside, so as to stop the charging process, such that the safety ofcharging can be ensured.

In an embodiment of the present disclosure, during the process that thepower adapter charges to the terminal, the switch unit is controlled toswitch off when the current sampling value is greater than apredetermined current value. In other words, during the process that thepower adapter charges to the terminal, a determination is performed onthe current sampling value. When the current sampling value is greaterthan the predetermined current value, it indicates that the currentoutputted by the power adapter is too high. At this time, the poweradapter is controlled to stop charging the terminal by controlling theswitch unit to switch off. In other words, the over-current protectionof the power adapter is realized by controlling the switch unit toswitch off, thus ensuring the safety of charging.

Similarly, the terminal obtains the current sampling value by performingthe bidirectional communication with the power adapter via the secondcharging interface, and controls to stop charging the battery when thecurrent sampling value is greater than the predetermined current value.In other words, the charging control switch is controlled to be switchedoff at the terminal side, such that the charging process of the batteryis stopped, thus ensuring the safety of charging.

The second predetermined voltage value and the predetermined currentvalue may be set according to actual situations.

In embodiments of the present disclosure, the status information of theterminal includes the electric quantity of the battery, the temperatureof the battery, the voltage/current of the battery of the terminal,interface information of the terminal and information on a pathimpedance of the terminal.

In detail, the power adapter can be coupled to the terminal via auniversal serial bus (USB) interface. The USB interface may be a generalUSB interface, or a micro USB interface. A data wire in the USBinterface is configured as the data wire in the first charginginterface, and configured for the bidirectional communication betweenthe power adapter and the terminal. The data wire may be D+ and/or D−wire in the USB interface. The bidirectional communication may refer toan information interaction performed between the power adapter and theterminal.

The power adapter performs the bidirectional communication with theterminal via the data wire in the USB interface, so as to determine tocharge the terminal in the second charging mode.

As an embodiment, when the power adapter performs the bidirectionalcommunication with the terminal via the first charging interface so asto determine to charge the terminal in the second charging mode, thepower adapter sends a first instruction to the terminal. The firstinstruction is configured to query the terminal whether to start thesecond charging mode.

The power adapter receives a first reply instruction from the terminal.The first reply instruction is configured to indicate that the terminalagrees to start the second charging mode.

As an embodiment, before the power adapter sends the first instructionto the terminal, the power adapter charges the terminal in the firstcharging mode. When the power adapter determines that a chargingduration of the first charging mode is greater than a predeterminedthreshold, the power adapter sends the first instruction to theterminal.

It should be understood that, when the power adapter determines that acharging duration of the first charging mode is greater than apredetermined threshold, the power adapter may determine that theterminal has identified it as a power adapter, such that the fastcharging query communication may start.

As an embodiment, the power adapter is controlled to adjust a chargingcurrent to a charging current corresponding to the second charging modeby controlling the switch unit. Before the power adapter charges theterminal with the charging current corresponding to the second chargingmode, a bidirectional communication is performed with the terminal viathe first charging interface to determine a charging voltagecorresponding to the second charging mode, and the power adapter iscontrolled to adjust a charging voltage to the charging voltagecorresponding to the second charging mode.

As an embodiment, performing the bidirectional communication with theterminal via the first charging interface to determine the chargingvoltage corresponding to the second charging mode includes: sending bythe power adapter a second instruction to the terminal, receiving by thepower adapter a second reply instruction sent from the terminal, anddetermining by the power adapter the charging voltage corresponding tothe second charging mode according to the second reply instruction. Thesecond instruction is configured to query whether a current outputvoltage of the power adapter is suitable for being used as the chargingvoltage corresponding to the second charging mode. The second replyinstruction is configured to indicate that the current output voltage ofthe power adapter is suitable, high or low.

As an embodiment, before controlling the power adapter to adjust thecharging current to the charging current corresponding to the secondcharging mode, the charging current corresponding to the second chargingmode is determined by performing the bidirectional communication withthe terminal via the first charging interface.

As an embodiment, determining the charging current corresponding to thesecond charging mode by performing the bidirectional communication withthe terminal via the first charging interface includes: sending by thepower adapter a third instruction to the terminal, receiving by thepower adapter a third reply instruction sent from the terminal anddetermining by the power adapter the charging current corresponding tothe second charging mode according to the third reply instruction. Thethird instruction is configured to query a maximum charging currentsupported by the terminal. The third reply instruction is configured toindicate the maximum charging current supported by the terminal.

The power adapter may determine the above maximum charging current asthe charging current corresponding to the second charging mode, or mayset the charging current as a charging current less than the maximumcharging current.

As an embodiment, during the process that the power adapter charges theterminal in the second charging mode, the bidirectional communication isperformed with the terminal via the first charging interface, so as tocontinuously adjust a charging current outputted to the battery from thepower adapter by controlling the switch unit.

The power adapter may query the status information of the terminalcontinuously, so as to adjust the charging current continuously, forexample, query the voltage of the battery of the terminal, the electricquantity of the battery, etc.

As an embodiment, performing the bidirectional communication with theterminal via the first charging interface to continuously adjust thecharging current outputted to the battery from the power adapter bycontrolling the switch unit includes: sending by the power adapter afourth instruction to the terminal, receiving by the power adapter afourth reply instruction sent by the terminal, and adjusting thecharging current by controlling the switch unit according to the currentvoltage of the battery. The fourth instruction is configured to query acurrent voltage of the battery in the terminal. The fourth replyinstruction is configured to indicate the current voltage of the batteryin the terminal.

As an embodiment, adjusting the charging current by controlling theswitch unit according to the current voltage of the battery includes:adjusting the charging current outputted to the battery from the poweradapter to a charging current value corresponding to the current voltageof the battery by controlling the switch unit according to the currentvoltage of the battery and a predetermined correspondence betweenbattery voltage values and charging current values.

In detail, the power adapter may store the correspondence betweenbattery voltage values and charging current values in advance.

As an embodiment, during the process that the power adapter charges theterminal in the second charging mode, it is determined whether there isa poor contact between the first charging interface and the secondcharging interface by performing the bidirectional communication withthe terminal via the first charging interface. When it is determinedthat there is the poor contact between the first charging interface andthe second charging interface, the power adapter is controlled to quitthe second charging mode.

As an embodiment, before determining whether there is the poor contactbetween the first charging interface and the second charging interface,the power adapter receives information indicating a path impedance ofthe terminal from the terminal. The power adapter sends a fourthinstruction to the terminal. The fourth instruction is configured toquery a current voltage of the battery in the terminal. The poweradapter receives a fourth reply instruction sent by the terminal. Thefourth reply instruction is configured to indicate the current voltageof the battery in the terminal. The power adapter determines a pathimpedance from the power adapter to the battery according to an outputvoltage of the power adapter and the current voltage of the battery anddetermines whether there is the poor contact between the first charginginterface and the second charging interface according to the pathimpedance from the power adapter to the battery, the path impedance ofthe terminal, and a path impedance of a charging wire between the poweradapter and the terminal.

As an embodiment, before the power adapter is controlled to quit thesecond charging mode, a fifth instruction is sent to the terminal. Thefifth instruction is configured to indicate that there is the poorcontact between the first charging interface and the second charginginterface.

After sending the fifth instruction, the power adapter may quit thesecond charging mode or reset.

The fast charging process according to embodiments of the presentdisclosure is described from the perspective of the power adapter, andthen the fast charging process according to embodiments of the presentdisclosure will be described from the perspective of the terminal in thefollowing.

In embodiments of the present disclosure, the terminal supports thefirst charging mode and the second charging mode. The charging currentof the second charging mode is greater than that of the first chargingmode. The terminal performs the bidirectional communication with thepower adapter via the second charging interface such that the poweradapter determines to charge the terminal in the second charging mode.The power adapter outputs according to a charging current correspondingto the second charging mode, for charging the battery in the terminal.

As an embodiment, performing by the terminal the bidirectionalcommunication with the power adapter via the second charging interfacesuch that the power adapter determines to charge the terminal in thesecond charging mode includes: receiving by the terminal the firstinstruction sent by the power adapter, in which the first instruction isconfigured to query the terminal whether to start the second chargingmode; sending by the terminal a first reply instruction to the poweradapter. The first reply instruction is configured to indicate that theterminal agrees to start the second charging mode.

As an embodiment, before the terminal receives the first instructionsent by the power adapter, the battery in the terminal is charged by thepower adapter in the first charging mode. When the power adapterdetermines that a charging duration of the first charging mode isgreater than a predetermined threshold, the terminal receives the firstinstruction sent by the power adapter.

As an embodiment, before the power adapter outputs according to thecharging current corresponding to the second charging mode for chargingthe battery in the terminal, the terminal performs the bidirectionalcommunication with the power adapter via the second charging interface,such that the power adapter determines the charging voltagecorresponding to the second charging mode.

As an embodiment, performing by the terminal the bidirectionalcommunication with the power adapter via the second charging interfacesuch that the power adapter determines the charging voltagecorresponding to the second charging mode includes: receiving by theterminal a second instruction sent by the power adapter, and sending bythe terminal a second reply instruction to the power adapter. The secondinstruction is configured to query whether a current output voltage ofthe power adapter is suitable for being used as the charging voltagecorresponding to the second charging mode. The second reply instructionis configured to indicate that the current output voltage of the poweradapter is suitable, high or low.

As an embodiment, before the terminal receives the charging currentcorresponding to the second charging mode from the power adapter forcharging the battery in the terminal, the terminal performs thebidirectional communication with the power adapter via the secondcharging interface, such that the power adapter determines the chargingcurrent corresponding to the second charging mode.

Performing by the terminal the bidirectional communication with thepower adapter via the second charging interface such that the poweradapter determines the charging current corresponding to the secondcharging mode includes: receiving by the terminal a third instructionsent by the power adapter, in which the third instruction is configuredto query a maximum charging current supported by the terminal; sendingby the terminal a third reply instruction to the power adapter, in whichthe third reply instruction is configured to indicate the maximumcharging current supported by the terminal, such that the power adapterdetermines the charging current corresponding to the second chargingmode according to the maximum charging current.

As an embodiment, during a process that the power adapter charges theterminal in the second charging mode, the terminal performs thebidirectional communication with the power adapter via the secondcharging interface, such that the power adapter continuously adjusts acharging current outputted to the battery.

Performing by the terminal the bidirectional communication with thepower adapter via the second charging interface such that the poweradapter continuously adjusts a charging current outputted to the batteryincludes: receiving by the terminal a fourth instruction sent by thepower adapter, in which the fourth instruction is configured to query acurrent voltage of the battery in the terminal; sending by the terminala fourth reply instruction to the power adapter, in which the fourthreply instruction is configured to indicate the current voltage of thebattery in the terminal, such that the power adapter continuouslyadjusts the charging current outputted to the battery according to thecurrent voltage of the battery.

As an embodiment, during the process that the power adapter charges theterminal in the second charging mode, the terminal performs thebidirectional communication with the control unit, such that the poweradapter determines whether there is a poor contact between the firstcharging interface and the second charging interface.

Performing by the terminal the bidirectional communication with thepower adapter, such that the power adapter determines whether there isthe poor contact between the first charging interface and the secondcharging interface includes: receiving by the terminal a fourthinstruction sent by the power adapter, in which the fourth instructionis configured to query a current voltage of the battery in the terminal;sending by the terminal a fourth reply instruction to the power adapter,in which the fourth reply instruction is configured to indicate thecurrent voltage of the battery in the terminal, such that the poweradapter determines whether there is the poor contact between the firstcharging interface and the second charging interface according to anoutput voltage of the power adapter and the current voltage of thebattery.

As an embodiment, the terminal receives a fifth instruction sent by thepower adapter. The fifth instruction is configured to indicate thatthere is the poor contact between the first charging interface and thesecond charging interface.

In order to initiate and adopt the second charging mode, the poweradapter may perform a fast charging communication procedure with theterminal, for example, by one or more handshakes, so as to realize thefast charging of battery. Referring to FIG. 10, the fast chargingcommunication procedure according to embodiments of the presentdisclosure and respective stages in the fast charging process will bedescribed in detail. It should be understood that, communication actionsor operations illustrated in FIG. 10 are merely exemplary. Otheroperations or various modifications of respective operations in FIG. 10can be implemented in embodiments of the present disclosure. Inaddition, respective stages in FIG. 10 may be executed in an orderdifferent from that illustrated in FIG. 10, and it is unnecessary toexecute all the operations illustrated in FIG. 10. It should be notedthat, a curve in FIG. 10 represents a variation trend of a peak value ora mean value of the charging current, rather than a curve of actualcharging current.

In conclusion, with the charging method for a terminal according toembodiments of the present disclosure, the power adapter is controlledto output the third voltage with the third pulsating waveform whichmeets the charging requirement, and the third voltage with the thirdpulsating waveform outputted by the power adapter is directly applied tothe battery of the terminal, thus realizing fast charging to the batterydirectly by the pulsating output voltage/current.

In contrast to the conventional constant voltage and constant current, amagnitude of the pulsating output voltage/current changes periodically,such that a lithium precipitation of the lithium battery may be reduced,the service life of the battery may be improved, and a probability andintensity of arc discharge of a contact of a charging interface may bereduced, the service life of the charging interface may be prolonged,and it is beneficial to reduce polarization effect of the battery,improve charging speed, and decrease heat emitted by the battery, thusensuring a reliability and safety of the terminal during the charging.Moreover, since the power adapter outputs the voltage with the pulsatingwaveform, it is unnecessary to provide an electrolytic condenser in thepower adapter, which not only realizes simplification andminiaturization of the power adapter, but also decreases cost greatly.

In the specification of the present disclosure, it is to be understoodthat terms such as “central,” “longitudinal,” “lateral,” “length,”“width,” “thickness,” “upper,” “lower,” “front,” “rear,” “left,”“right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,”“clockwise,” “counterclockwise,” “axial,” “radial,” and “circumference”refer to the orientations and location relations which are theorientations and location relations illustrated in the drawings, and fordescribing the present disclosure and for describing in simple, andwhich are not intended to indicate or imply that the device or theelements are disposed to locate at the specific directions or arestructured and performed in the specific directions, which could not tobe understood to the limitation of the present disclosure.

In addition, terms such as “first” and “second” are used herein forpurposes of description and are not intended to indicate or implyrelative importance or significance or to imply the number of indicatedtechnical features. Thus, the feature defined with “first” and “second”may comprise one or more of this feature. In the description of thepresent disclosure, “a plurality of” means two or more than two, unlessspecified otherwise.

In the present disclosure, unless specified or limited otherwise, theterms “mounted,” “connected,” “coupled,” “fixed” and the like are usedbroadly, and may be, for example, fixed connections, detachableconnections, or integral connections; may also be mechanical orelectrical connections; may also be direct connections or indirectconnections via intervening structures; may also be inner communicationsof two elements, which can be understood by those skilled in the artaccording to specific situations.

In the present disclosure, unless specified or limited otherwise, astructure in which a first feature is “on” or “below” a second featuremay include an embodiment in which the first feature is in directcontact with the second feature, and may also include an embodiment inwhich the first feature and the second feature are not in direct contactwith each other, but are contacted via an additional feature formedtherebetween. Furthermore, a first feature “on,” “above,” or “on top of”a second feature may include an embodiment in which the first feature isright or obliquely “on,” “above,” or “on top of” the second feature, orjust means that the first feature is at a height higher than that of thesecond feature; while a first feature “below,” “under,” or “on bottomof” a second feature may include an embodiment in which the firstfeature is right or obliquely “below,” “under,” or “on bottom of” thesecond feature, or just means that the first feature is at a heightlower than that of the second feature.

Reference throughout this specification to “an embodiment,” “someembodiments,” “one embodiment”, “another example,” “an example,” “aspecific example,” or “some examples,” means that a particular feature,structure, material, or characteristic described in connection with theembodiment or example is included in at least one embodiment or exampleof the present disclosure. Thus, the appearances of the phrases such as“in some embodiments,” “in one embodiment”, “in an embodiment”, “inanother example,” “in an example,” “in a specific example,” or “in someexamples,” in various places throughout this specification are notnecessarily referring to the same embodiment or example of the presentdisclosure. Furthermore, the particular features, structures, materials,or characteristics may be combined in any suitable manner in one or moreembodiments or examples.

Those skilled in the art may be aware that, in combination with theexamples described in the embodiments disclosed in this specification,units and algorithm steps can be implemented by electronic hardware, ora combination of computer software and electronic hardware. In order toclearly illustrate interchangeability of the hardware and software,components and steps of each example are already described in thedescription according to the function commonalities. Whether thefunctions are executed by hardware or software depends on particularapplications and design constraint conditions of the technicalsolutions. Persons skilled in the art may use different methods toimplement the described functions for each particular application, butit should not be considered that the implementation goes beyond thescope of the present disclosure.

Those skilled in the art may be aware that, with respect to the workingprocess of the system, the device and the unit, reference is made to thepart of description of the method embodiment for simple and convenience,which are described herein.

In embodiments of the present disclosure, it should be understood that,the disclosed system, device and method may be implemented in other way.For example, embodiments of the described device are merely exemplary.The partition of units is merely a logical function partitioning. Theremay be other partitioning ways in practice. For example, several unitsor components may be integrated into another system, or some featuresmay be ignored or not implemented. Further, the coupling between eachother or directly coupling or communication connection may beimplemented via some interfaces. The indirect coupling or communicationconnection may be implemented in an electrical, mechanical or othermanner.

In embodiments of the present disclosure, it should be understood that,the units illustrated as separate components can be or not be separatedphysically, and components described as units can be or not be physicalunits, i.e., can be located at one place, or can be distributed ontomultiple network units. It is possible to select some or all of theunits according to actual needs, for realizing the objective ofembodiments of the present disclosure.

In addition, each functional unit in the present disclosure may beintegrated in one progressing module, or each functional unit exists asan independent unit, or two or more functional units may be integratedin one module.

If the integrated module is embodied in software and sold or used as anindependent product, it can be stored in the computer readable storagemedium. Based on this, the technical solution of the present disclosureor a part making a contribution to the related art or a part of thetechnical solution may be embodied in a manner of software product. Thecomputer software produce is stored in a storage medium, including someinstructions for causing one computer device (such as a personal PC, aserver, or a network device etc.) to execute all or some of steps of themethod according to embodiments of the present disclosure. Theabove-mentioned storage medium may be a medium able to store programcodes, such as, USB flash disk, mobile hard disk drive (mobile HDD),read-only memory (ROM), random-access memory (RAM), a magnetic tape, afloppy disc, an optical data storage device, and the like.

Although explanatory embodiments have been illustrated and described, itwould be appreciated by those skilled in the art that the aboveembodiments cannot be construed to limit the present disclosure, andchanges, alternatives, and modifications can be made in the embodimentswithout departing from spirit, principles and scope of the presentdisclosure.

What is claimed is:
 1. A charging control method, comprising:controlling a first rectifier to rectify an alternating current (AC) tooutput a voltage with a first pulsating waveform; outputting a controlsignal to a switch unit, such that the switch unit modulate the voltagewith the first pulsating waveform without filtering based on the controlsignal; controlling a transformer to perform voltage transformation onthe modulated voltage with the first pulsating waveform to output avoltage with a second pulsating waveform; and controlling a secondrectifier to rectify the voltage with the second pulsating waveform tooutput a voltage with a third pulsating waveform to a chargeablebattery, wherein the third pulsating waveform keeps synchronous with thefirst pulsating waveform of the modulated voltage.
 2. The method ofclaim 1, further comprising: controlling a first sampling circuit tosample current and/or voltage output by the second rectifier, to acquirea first current sampling value and/or a first voltage sampling value;and adjusting a duty ratio of the control signal based on the firstcurrent sampling value and/or the first voltage sampling value.
 3. Themethod of claim 1, further comprising: acquiring status information ofthe chargeable battery; and adjusting a duty ratio of the control signalbased on the status information.
 4. The method of claim 1, furthercomprising: controlling a second sampling circuit to sample the voltagewith the first pulsating waveform to acquire a second voltage samplingvalue; and when the second voltage sampling value is greater than apreset voltage value, controlling the switch unit to switch on for apredetermined time period, for performing a discharge on surge voltage,spike voltage in the first voltage with the first pulsating waveform. 5.The method of claim 1, further comprising: outputting the control signalto the switch unit intermittently.
 6. The method of claim 2, furthercomprising: outputting the control signal to the switch unitintermittently based on the first current sampling value and/or thefirst voltage sampling value.
 7. The method of claim 1, furthercomprising: controlling the transformer to perform voltagetransformation on the modulated voltage with the first pulsatingwaveform to output a voltage with a fourth pulsating waveform via anauxiliary winding of the transformer; and controlling a power supplyunit to convert the voltage with the fourth pulsating waveform to outputa direct current (DC).
 8. The method of claim 1, further comprising:determining a charging mode, the charging mode comprising a firstcharging mode and a second charging mode, a charging speed of the firstcharging mode is less than that of the second charging mode.
 9. Themethod of claim 8, further comprising: when the first charging mode isdetermined, controlling a controllable switch to switch on, wherein thecontrollable switch and a filtering unit are in series, and thecontrollable switch and the filtering unit in series are coupled to anoutput end of the second rectifier; and when the second charging mode isdetermined, controlling the controllable switch to switch off.
 10. Themethod of claim 8, further comprising: when the second charging mode isdetermined, acquiring a charging current and/or a charging voltage ofthe second charging mode; and adjusting a duty ratio of the controlsignal based on the charging current and/or the charging voltage of thesecond charging mode.
 11. A charging device, comprising: a firstrectifier, configured to rectify an alternating current (AC) to output avoltage with a first pulsating waveform; a switch unit; a control unit,configured to output a control signal to the switch unit, such that theswitch unit modulate the voltage with the first pulsating waveformwithout filtering based on the control signal; a transformer, configuredto perform voltage transformation on the modulated voltage with thefirst pulsating waveform to output a voltage with a second pulsatingwaveform; and a second rectifier, configured to rectify the voltage withthe second pulsating waveform to output a voltage with a third pulsatingwaveform to a chargeable battery, wherein the third pulsating waveformkeeps synchronous with the first pulsating waveform of the modulatedvoltage.
 12. The device of claim 11, further comprising: a firstsampling circuit; wherein the control unit is further configured tocontrol the first sampling circuit to sample current and/or voltageoutput by the second rectifier, to acquire a first current samplingvalue and/or a first voltage sampling value, and adjust a duty ratio ofthe control signal based on the first current sampling value and/or thefirst voltage sampling value.
 13. The device of claim 11, wherein thecontrol unit is further configured to: acquire status information of thechargeable battery; and adjust a duty ratio of the control signal basedon the status information.
 14. The device of claim 11, furthercomprising: a second sampling circuit; wherein the control unit isfurther configured to control the second sampling circuit to sample thevoltage with the first pulsating waveform to acquire a second voltagesampling value, and when the second voltage sampling value is greaterthan a preset voltage value, control the switch unit to switch on for apredetermined time period, for performing a discharge on surge voltage,spike voltage in the first voltage with the first pulsating waveform.15. The device of claim 11, wherein the control unit is furtherconfigured to: output the control signal to the switch unitintermittently.
 16. The device of claim 12, wherein the control unit isfurther configured to: output the control signal to the switch unitintermittently based on the first current sampling value and/or thefirst voltage sampling value.
 17. The device of claim 11, wherein thecontrol unit is further configured to: determine a charging mode, thecharging mode comprising a first charging mode and a second chargingmode, a charging speed of the first charging mode is less than that ofthe second charging mode.
 18. The device of claim 17, furthercomprising: a controllable switch and a filtering unit, wherein thecontrollable switch and the filtering unit are in series, and thecontrollable switch and the filtering unit in series are coupled to anoutput end of the second rectifier; wherein the control unit is furtherconfigured to: when the first charging mode is determined, control thecontrollable switch to switch on, and when the second charging mode isdetermined, control the controllable switch to switch off.
 19. Thedevice of claim 17, wherein the control unit is further configured to:when the second charging mode is determined, acquire a charging currentand/or a charging voltage of the second charging mode; and adjust a dutyratio of the control signal based on the charging current and/or thecharging voltage of the second charging mode.
 20. A non-transitorycomputer readable storage medium having stored therein programinstructions, wherein the instructions are configured to be invoked by acharging device to realize acts of: controlling a first rectifier torectify an alternating current (AC) to output a voltage with a firstpulsating waveform; outputting a control signal to a switch unit, suchthat the switch unit modulate the voltage with the first pulsatingwaveform without filtering based on the control signal; controlling atransformer to perform voltage transformation on the modulated voltagewith the first pulsating waveform to output a voltage with a secondpulsating waveform; and controlling a second rectifier to rectify thevoltage with the second pulsating waveform to output a voltage with athird pulsating waveform to a chargeable battery, wherein the thirdpulsating waveform keeps synchronous with the first pulsating waveformof the modulated voltage.